POMONA The Member-Written, Quarterly Journal of North American Fruit Explorers (NAFEX) Vol. XLVI, No. 3, Summer 2013
Fruit Tree Polycultures Trevor Newman email@example.com (P) 248-535-9419 (F) 248-625-7676 The Fruit Nut | http://www.thefruitnut.com
Unlike monocultures, polycultures contain diverse mixtures of species growing together in symbiosis. Creating polycultures around fruit trees can reduce the need for offsite inputs, increase biodiversity in the orchard, and provide various secondary yields such as medicinal herbs, perennial vegetables, and much more. Establishing polycultures around fruit trees is all about analyzing the needs of the tree and matching those needs to the functions of various support species or ‘companion plants.’ The aim is to provide the basic needs of the tree (fertility, pest management, weed control, etc.) by using biological resources. Instead of ‘planting a fruit tree,’ we can think of this integrated approach as ‘planting an ecosystem’.
Dynamic accumulators are plants whose deep taproots mine hard-to-reach minerals from the soil and deposit them in their aerial parts. These plants can be grown around the base of fruit trees and managed on a ‘chop-n-drop’ basis whereby their aerial parts are occasionally cut and spread as mulch directly beneath the trees. Comfrey (Symphytum officinale) is a great example of a dynamic accumulator that is high in calcium, phosphorus, and manganese. I put at least one comfrey plant at the base or around the drip line of each tree and generally cut them back for mulch 3-4 times throughout the growing season.
Nitrogen-fixing plants are commonly used in organic agriculture as cover crops and green manure. The same principles can be applied to the orchard by using nitrogen fixing trees, shrubs, and herbs to act as nurse crops for young fruit trees. A great multi-purpose nitrogen fixer is goumi (Eleagnus multiflora), which produces an early-season berry and provides an abundance of nectary flowers which honeybees love. When goumi and other nitrogen fixers are cut down, their roots respond by releasing a plume of nitrogen into the surrounding soil. Fruit trees and other crop plants can tap into this fertility source.
Groundcover plants are excellent weed suppressors and should be integrated throughout the orchard understory to act as living mulch while excluding any potential for weeds to grow. Applemint (Mentha suaveolens) and white clover (Trifolium repens) are two groundcovers that can be effectively integrated with orchard grass to create a dense mat. Creeping comfrey is an excellent groundcover that spreads indefinitely, can tolerate shade, and also serves as a dynamic accumulator.
Another class of functional plants are known as insectaries. These are plants that provide fodder for beneficial and predatory insects. By attracting these ‘good guys’ to the orchard we can increase pollination and limit pest outbreaks by encouraging a balance among predator and prey populations. Plants in the Apiaceae family (carrot, lovage, etc.) and plants in the Asteraceae family (yarrow, coneflower, etc.) are especially good at attracting predatory insects like parasitic wasps, lace wings, and lady beetles. Having insectary plants flowering at different times throughout the year ensures that beneficial insects will have a plentiful supply of food and reason to stick around.
The core of good polyculture design lies in a basic understanding of ecology and plant functions. Polycultures mimic functional interconnections found in natural ecosystems while producing an abundance of yields and reducing off site inputs. Visit www.apiosinstitute.org to see numerous case studies and find out more about designing fruit tree polycultures.
Michael Phillips is an organic orchardist, consultant, and writer who has titled two popular fruit growing books—The Apple Grower (Chelsea Green 2005) and The Holistic Orchard (Chelsea Green 2011). His books have been crucial resources for me in my orcharding endeavors. Both books describe innovative and cutting edge strategies for managing orchards in an ecologically regenerative way that doesn’t rely upon synthetic fertilizers and toxic biocides. The Holistic Orchard DVD guides viewers on a highly informative and visually stimulating tour through a year in the orchard. Phillips takes us around his New Hampshire farm through the four seasons showing many of the happenings of a healthy orchard ecosystem.
Phillips jovially shares his 25+ years of orcharding experience in over four hours of engaging video footage. He covers everything from planting and propagation to pruning and harvesting. This instructional video will be an invaluable resource for growers of all skill levels. Phillips lays the foundation for an ecological orcharding protocol that can be replicated and adapted from region to region. He emphasizes an integrated, ‘health based approach’, which like holistic medicine— is all about boosting the health of the entire ecosystem from the fungi and microorganisms to the birds and insects. Phillips goes through the best practices for managing a number of common orchard pests like apple tree borer, plum curculio, and codling moth. Furthermore he breaks down the life cycle of each pest, shows what to look for, and explains when the best times are to intervene in that pests life cycle. This is the type of detail you will find in the Holistic Orchard DVD.
The depth and range of Phillip’s knowledge will surely clarify any hard-to-grasp concepts for beginner and advanced orchardists alike. Phillips not only offers an alternative to today’s conventional, chemical-based orcharding approach, but he presents the information in an exciting and easy-to-digest way that will motivate any gardener or fruit grower to think more holistically. I am grateful for Michael’s contributions to the world of fruit growing and I highly recommend this DVD. Whether you’re dealing with a small backyard orchard, a community orchard, or a production scale farm this video will provide valuable insights. Click here to purchase a copy of the DVD and to learn more about Michael Phillips visit his websites at: herbsandapples.com and groworganicapples.com.
Winter is coming and you can feel it in the air. While Hurricane Sandy was wreaking havoc on the east coast Michigan got hit with serious winds, heavy rain, and some hail. That storm swooped away the remaining tree leaves bringing a conclusion to the beautiful display of fall colors. Now the bareness is kicking in. I’ve been struggling to find time to write amongst the busyness of closing down the gardens and getting everything ready for winter. You have to make hay when the sun shines- soon enough we’ll be snowed in.
A LOT has been going on, though. Many renovations have been made in the garden/orchard as well as some new plantings. My company has been doing well this fall and we’ve hosted some exciting workshops and secured some enthusiastic new clients that are ready to take on and transform their own landscapes. The elections have just passed, thankfully, and obviously everybody has their different views on voting…but we can all use this time as a reminder that perhaps the most effective way to vote and cast your voice is with your everyday actions. ‘Vote with your dollar’ is a powerful saying. We all have an opportunity to be the change we wish to see. Make positive changes in your own community, small or large.
Thats a wrap for my political rant; this is after all a website about fruit and orcharding, not politics. I vote for apples. Speaking of apples, I just finished the latest episode of the The Fruit Nut Podcastwith Michael Phillips, the author of The Apple Grower and The Holistic Orchard. It was a great conversation and Michael shared so much valuable information. We talked about holistic fruit tree care, community orchards, and more. CLICK HERE to listen to the interview. Unfortunately the past three episodes have been recorded with a low quality microphone so the audio on my end breaks up a lot and doesn’t sound that great. HOWEVER, I am investing in a new recording system to produce much cleaner audio. Look forward to episode 4 withLee Reich.
Here are some recent photos of field trips, events, and happenings in the garden…
Now the autumnal shift is fully present and unavoidable as the trees show their gorgeous display of fall colors and days get cooler. However this is still a busy time of year…even with some 75% of the fruit crops wiped out there is still a bit to harvest. Before we take a look at that, I’d like to announce the addition of two new pieces to the Articles page, one titled Making Ink From Berries by guest writer Dana Driscoll, and the other a small-scale alley crop photo essay by yours truly. Speaking of new content, I am also excited to share with you my latest audio podcast with the American persimmon fanatic, Jerry Lehman! Click here to listen to the podcastand stay tuned for Episode 3 with Michael Phillips, the author of The Holistic Orchard.
That pretty much covers the latest in terms of new content. Was at a client’s site the other day doing a check up and found some exciting things. This was a site we installed 3 years ago and haven’t gone back much since then, so whenever we make a visit its always surprising to see whats done well. While visiting we also decided to harvest autumnberries from a bountiful population along the edge of her street. Here are some photos from that adventure…
Autumnberry is a truly abundant wild food that is loaded with nutrients and so widely available. More people need to start harvesting it. There is a big debate with autumnberry and many other plant species— some folks believe eradication is necessary because these plants are “invasive”, which is an entirely non-scientific claim that lacks any ecological footing. This is a big issue and we won’t get into it too much right now, but I would like to point out one thing. In the case for autumnberry, the plant arrived to NA back in the 70’s and was promoted largely by the USDA and conservation districts, NOW the same folks who encouraged the planting and dissemination of autumnberry are the ones promoting its eradication…SO, to me it seems only rational to NOT put full trust in these organizations and institutions. Who knows what will happen 30 years from now if herbicide applications are continued in radical attempts to eradicate opportunistic plants? All I am saying is we need to be incredibly mindful when we intervene on this level and have great forethought into potential future outcomes…good or bad. That concludes my rant for now.
Speaking of jam, just the other day I harvested some mountain ash berries from a tree my parents planted some 25+ years ago. The yields were down this year but there was
enough to experiment making a small batch of jam. If you’ve ever tried mountain ash berries then you know they’re incredibly astringent and barely palatable(there are some varieties and hybrids which are better for eating). In past years I’ve made mountain ash mead and used the tree as a rootstock for shipova(more to come on that soon). But I never really ‘ate’ the berries. So I tried making a batch of jam…and…it tastes awful. No matter how much sugar you add the astringency just intensifies. Supposedly the berries get sweeter with a frost… and they are said to be high in vitamin C. I think its more useful as medicine then food.
Another not-so-edible berry…is the yew berry. Which in fact contains a highly poisonous seed…but the red jelly-like flesh is said to be edible. And it is edible, I am living proof. Out of curiosity I began nibbling on the berries this fall and I found they’re actually quite good! Very sweet with a mild flavor. The texture is slimy. An interesting relative that I’ve only read about is Japanese plum yew(Cephalotaxus harringtonia); this one is said to produce larger fruits that are fully edible, seed and all.
Today marks the autumnal equinox and now its official— fall is here! In retrospect the summer seemed to have went by in fast motion as it started abruptly with an early spring and now its concluding just as swiftly. These periods of drastic change are incredibly powerful and sometimes the shifting energy can be difficult to deal with but we try our best. I have been traveling for the past few weeks, first on a trip to VT to stay at Whole Systems Design research farm and then touring throughout northwest MI doing some consulting, seminars, and catching up with friends and colleagues. Summer seems to have ended during the weeks on the road and now that I’m back its satisfying to spend time walking through the gardens observing, harvesting, and contemplating. There is still a lot to be had for the 2012 gardening season but cold nights dipping into the low 40’s pose major threats to those vine-ripening tomatoes and unripe figs(which sadly won’t ripen). Its the time of year to move inward, wether that means collecting your ideas and dreams, or storing away the season’s bounty. In the next couple weeks I will be making jams & jellies, fermenting cabbage, carrots, and other root vegetables, as well as putting up other storable food items for the cold months ahead. The squirrels are busy burying nuts, luckily for them(and us!) its a bumper crop year for oaks. The best part is that sometimes they forget these burial sites and VOILA a cluster of oak trees appear a few seasons later. Ever since I’ve been growing fruit and gardening in general, this season stands out as the most unusual in terms of weather conditions, ripening dates, and so on. In the old apple orchard on my families land not an apple can be found. Not to say that all of the apples in SE MI were a bust, but these particular trees set very few if any. On a recent visit to a friend’s orchard outside of Ann Arbor, I discovered that his plum, apricot, peach, pear, and apple trees didn’t set a single fruit. On the contrary, the other day while driving through the hilly landscape of the grand Traverse bay in northern MI, the roadside orchard trees were laden with ripe apples. Perhaps this protected fruit growing region has somewhat of a buffer. Either way, its been an odd and eye-opening year. I keep thinking back to a principle we share in our Roots To Fruits talks…it goes: Value Diversity; we then expand and talk about the different facets of diversity(functional,biological,genetic,etc.) and the many values of having a diverse landscape, but now I’m referring to crop diversity in a garden-orchard. Its one of those years you wish you would’ve over-planted. Another interesting idea comes to mind that I’d like to share with you. While having a conversation with my buddy Ben Falk, he mentioned that there is a lot of talk about how tree-based agriculture is highly resilient in the face of an unpredictable climate and other instabilities but really when we depend on fruit, mast, or nut-producing trees we’re actually relying on the most delicate and vulnerable manifestation of nature— a flower. He makes a good point, and it can be clearly seen this year with crop loss due to drought, late frosts, and other climatic conditions. This reinforces the necessity for planting late-flowering trees like American persimmon and chestnut. I digress.
Several exciting ideas are brewing for new blog posts and articles so keep an eye out over the next couple weeks and expect much more as we move into the winter months. I will have some amazing guests coming on the podcast as well. For now I’ve decided to share some recent photos with quick captions that will hopefully give you an idea of what I’ve been up to as of late. May you have a happy and healthy seasonal transition!
Its been a few weeks since my last post and I’ve been itching to release some fresh ideas and photos. Things have been a bit crazy lately with selling plants at the farmers markets and working on new Roots To Fruits jobs. Its all very good, just a bit tiring at times. So now, on this new moon, I’ve found some time to put out. Just as everything goes in phases and cycles so does my motivation to write, and with the waxing moon my energy towards writing and managing the blog is on the rise! So expect some frequent posting over the next few weeks.
Its mid-august and the groundcherries in my garden are starting to litter the ground once again. This has been a tradition for the past several seasons; in fact last year the garden was so inudated w/ self-seeded ground cherries, that access became an issue! But what are ground cherries? Being a member of the Solanaceae family they bear some resemblance to tomatillos or cherry tomatoes except with a much fruitier flavor. Botanically speaking tomatoes are technically a fruit, although they’re often referred to as a vegetable…groundcherries, however, don’t fall short of the fruit category. The common ground cherry(Physalis peruviana), also called cape gooseberry, not to be mistaken with true gooseberries(Ribes spp.), is a self seeding annual that can become rather weedy. Physalis heterphylla is a perennial relative that grows wild throughout eastern NA. I have
found them growing a few times in MI, and Ken Asmus of Oikos Tree Crops now sells the perennial form. Even the annual forms seem to ‘perennialize’ in the sense that they volunteer each year and reliably come back. They’re called ground cherries because they fall to the ground when fully ripe. They can then be collected, dehusked, and eaten fresh. I’ve also heard them called husk cherries because they grow inside a papery protective husk. Nature’s wrapper. The flavor is like the sweetest of tomatoes with fruity-pineapple notes. They are about the size of a grape tomato and contain several small seeds which are barely noticeable. Ground cherries are great dehydrated and I’ve been toying with the idea of using them in salsa, jelly, and wine. Mmmm…
Now that summer has peaked and is waning, we’ve concluded most of the berry pickin’; cane fruits are pretty much done, besides the fall bearing raspberries, blueberries are dwindling but still available, and the Ribes, besides the latest of gooseberries, are now a distant memory. Fortunately they’re blessings are preserved in jams and jellies! The
changing seasons can be difficult to deal with, but its a righteous reminder of the impermanence of all things. Actually its a good way to practice non-attachment. I really, really, am enjoying all of these wonderful zucchinis, but they too will pass! Nothing lasts forever and thats the beauty of it. As small fruits and berries are largely coming to an end, the stone fruits are coming in, and early apples are beginning to ripen. I was in Detroit two weeks ago and was
delightfully surprised to find the number of ripe apples. The odd season paired with the Detroit microclimate created super conditions for tree fruit. Even the peaches weren’t phased by the early season warm spells and late frosts. We even found peach seedlings setting fruit in alleys. Want to start growing fruit? Move to Detroit.
My peach trees didn’t set any fruit this year. Fortunately a few local growers managed to get a small percentage of the usual crop…just enough to bring to market. So the past two weeks I’ve been buying containers of peaches at the market. I belong to a goat milk share where I get a half gallon of organic raw goat milk each week. This week I decided to make some fresh cheese… I was left with a lot of whey. Today I made a lovely smoothy with one cup blueberries, two peaches, and one cup whey. No whey, yes whey… rich in flavor and rich in nutrients!
As promised, here is the blueberry-lavender jam recipe…very simple, no fuss recipe. Give it a try!
What You’ll Need:
8 cups fresh blueberries
1.5 cups organic sugar
1 tablespoon lavender flowers
1/4 cup lemon juice
Step #1: Crush washed blueberries in large cooking pot. Cook on medium heat for 5 minutes.
Step #2: Add sugar and lemon and bring to a boil. Reduce heat, add lavender and cook for 10-15 more minutes on medium heat. Stir consistently.
Step #3: Take off heat and fill jars; store in fridge or for long-term storage place jars in boiling water bath for 15 minutes.
Tips: some recipes suggest removing foam as the jam cooks; I’ve found blueberries to be low foam producers making this step unnecessary.
I choose to plant based on the moon using the biodynamic calendar AKA the Stella Natura. I’ve found much satisfaction(not to mention great results) in following the solunar calendar for my gardening activities. I also make medicine preparations like tinctures and salves on the new moon as to foster the lunar energy put out increasingly from that time until the next full moon. Aside from food, I’ve been curious about the medicinal uses of fruiting plants. Strawberry leaf is a great astrigent used in skin care products, raspberry leaf is high in tannins and has a slew of medicinal actions, and lastly, what I’m concerning myself with today— black currant leaf. Aside from the potent nutraceutical properties of Ribes nigrum fruit, the leaves also possess strong medicinal properties. According to one resource, “Black currant dried leaf is used for arthritis, gout, joint pain (rheumatism), diarrhea, colic, hepatitis and other liver ailments, convulsions, and disorders that cause swelling (inflammation) of the mouth and throat. Black currant dried leaf is also used for treating coughs, colds, and whooping cough; disinfecting the urine; promoting urine flow; treating bladder stones, and as a cleansing tea.” The leaves are astringent and have been used for treating skin blemishes like acne and eczema. Since the plants are just hanging out now and all the berries are long picked, I decided to harvest some leaves for making an alcohol extract.
The late Frank Cook talks briefly about the edible and medicinal uses of black currant…
An exciting new project recently sprouted forth after connecting with a local friend and fellow entrepreneur, Josh Cook. His company, Source Reality, offers products and service for facilitating individuals in connecting to their deepest nature, and reuniting with the source. They offer astrology readings, reiki healing, orgonite, and more. According to the Source Reality website: “Orgonite is the name given to powerful devices which attract negative etheric energy and transmute it into positive, life-giving energy. This is done through a mixture of metals and crystals that are sealed in a resin and formed in specific molds…”
Visit their website to learn more about these unique energy devices. We’re collaborating to do a research experiment using orgonite for influencing plant growth. I’ve conducted a small trial with two hardy kiwi vines grown in containers under identical soil, water, and light conditions… one, however, has an orgonite mold placed in the bottom of the 1gallon pot. We hypothesize that the energetic workings of the orgonite may effect plant growth in some way. Stay tuned for results.
The sun set is telling me to conclude this post and unwind for the evening. Please check back soon for more exciting posts, new articles, and upcoming audio podcasts! Happy growing…
Last week I did a post highlighting some of the unusual members of the Rubus genus, or more commonly known as brambles. I want to share one more of those rarities— Rubus odoratus AKA purple-flowering raspberry. Originally I started with one lowly plant from the edible forest garden at MSU’s Student Organic Farm. Now an ever expanding clump of purple flowering raspberry lives beneath the canopy of one of my peach trees. Its a lovely plant with attractive, almost star-shaped leaves and pretty pink flowers. Only problem is that the plants are shy to bear. The plants, and the fruits themselves, bear much resemblance to thimbleberry(R.parviflorus). Today I was able to munch on a few ripe berries and they had a pleasant nutty flavor reminiscent of a dried raspberry. Although unproductive, purple-flowering raspberry is a lovely ornamental none-the-less.
Whats more American than blueberries? In fact, blueberries symbolize American fruit
culture more than any other fruit and they’re one of the few commonly cultivated fruits which hails from this continent. They’re not only indigenous to North America but also heavily populated in the state of Michigan. The west side of the state is known for its blueberry farms and just like Maine is known for its wild lowbush blueberries(Vaccinium angustifolium), so is northern Michigan for its wild highbush blueberries(Vaccinium corymbosum). Blueberries are unique and varied in their tolerances and habitat preference… with lowbush blueberries in the northeast flourishing on rocky outcrops and highbush blueberries in the midwest growing in boggy wetlands, all the while cultivated blueberries find their happiest home in well drained sandy loams. But when speaking of wild highbush blueberries growing in Michigan, we almost always refer to them growing in wetland ecosystems. They like the high organic matter and steady moisture supply. Another factor, too, is the soil acidity found in these environments. Any gardener or farmer who has grown blueberries knows they prefer a low PH. This is their neediest of needs and the one condition they won’t perform well without.
This season has been magical when it comes to blueberries. One of my clients who lives just minutes away has a beautiful wooded site with several acres. On the back part of the property a maple forest transitions to a boggy wetland and Chris(the homeowner) took me on a walk back there last year and pointed out a nice patch of blueberries that her and her kids had been harvesting from for the past few years. She invited me back to come picking and this year I took her up on it. My business partner and I made our way back there for the first time a few weeks ago and we spent a couple days picking. It was wonderful. A 2″x12″ plank meanders far enough above the ground as to keep one’s feet dry(in a wet year at least)while walking through the bog. We were grateful that she allowed us to pick from her spot. Many days ago when out picking we decided to explore the area more thoroughly. Through our exploration we came upon a much larger stand of wild blueberries. When I say large I literally mean 4-5 acres of almost entirely highbush blueberries! The expansiveness leads me to believe that the ecosystem is relatively stable and could’ve likely been this way for 50-100+ years. This is something you’d only dream of. For the first day or so I could hardly fathom the reality. Hundreds of mature, fruit laden bushes— waiting to be picked by some hungry birds, bears, or…humans! The blueberry gods blessed us indeed.
The thing that fascinates me most about these types of systems is the incredible amount of diversity. Since its an entirely feral ecosystem, all of the bushes grew from seed. This means each plant is genetically different from one another and represents a totally unique set of genes. Plant size, fruit size & color, flavor, disease resistance, and ripening time all vary drastically. On the contrary, in an agricultural setting clonally-propagated cultivars grow independently. We must remember, though, diversity is thespice of life, and every single cultivated blueberry variety ever developed was either selected or bred from these wild ancestors. If you’ve ever harvested wild blueberries then you probably know that the berries are smaller then the cultivated ones. My friend pointed out the other day how she’s thankful for modern agriculture because of the improvements made in berry size and productivity. I agree with her, but at the same time I treasure what these wild ones have perseveringly brought to this world. Plus, picking their fruit is a good practice in patience and allows one to become more in-tuned with nature. I love wild blueberries.
You may be wondering why this post got the title it did. Well, if you’ve read my previous posts then you realize that its been an odd year in regards to weather patterns. Early flowering, late frosts, and extended drought have caused some of my favorite fruits like cherries, mulberries, serviceberries, and black raspberries, to have very poor seasons. So, even in the roughest of years, the blueberries prevail (amongst others like currants and blackberries)! This attests to their adaptability and reliability. I recall Lee Reich mentioning in one of his books that blueberries, out of all the fruit crops, were one of his all-time favorites for this very reason. Currently I don’t have any blueberries planted in my garden, however they’re an up and coming addition! This spring I purchased six cultivars fromHartmann’s Plant Company in preparation for fall planting. Its smart to prepare your blueberry bed a few months in advance; this allows time for any appropriate PH adjustments to take place, unless of course you already have acidic soil.
I fancy fresh blueberries. Eating them out of hand is perhaps one of my greatest pleasures. The light semi-acid, yet complex, fruity flavor is something to write home about. After I eat blueberries I always feel energized and fully satisfied. This must have something to do with their high antioxidant properties. They’re also very cooling on a hot summer day. I’ve been eating fresh handfuls daily for the past 2+ weeks but I’ve also processed ’em into ice cream and more recently into blueberry-lavender jam(stay posted for recipes)!
It looks like the blueberry season will go for another 1-2 weeks and blackberries are coming into full swing. Fortunately the blackberry crop this year is looking mighty fine. More to come on that soon. I’m still harvesting what appears to be the last ripening flush from the primocane crop of golden raspberries; be on the lookout for golden raspberry jam!!! Until next time…
Eric Toensmeier is the author of Perennial Vegetables and the co author of Edible Forest Gardens Volumes 1/2. He has a wealth of knowledge when it comes to food forestry, permaculture design, and useful plants. What follows is an essay Eric recently wrote about the nitrogen fixing capacities of a variety of plants from different regions. This one’s especially good for the plant geek within you! Learn more by visiting Eric’s website www.perennialsolutions.org.
All Nitrogen Fixers Are Not Created Equal
Nitrogen fixing species are a cornerstone of food forestry and other permaculture practices. Through a partnership with symbiotic organisms in their roots, these plants can turn atmospheric nitrogen into nitrogen fertilizers useful to themselves but also becoming available to their neighbors over time through root die back, leaf fall, and chop and drop coppice management. While it does not replace the need to bring in phosphorus, calcium, and other nutrients depleted by harvests, this strategy provides a free source of an essential fertilizer.
Martin Crawford’s Creating a Forest Garden and Nitrogen Fixing Plants for Temperate Climates are excellent resources for calculating the percentage of nitrogen fixtures needed in order to supply all required nitrogen just from plants. Martin estimates this at 25 to 40% of plants in full sun or 50 to 80% of plants and shade, depending on the nitrogen needs of the crops being grown.
Now I’m going to throw another wrench into your calculations. I’ve known for some time that the amount of nitrogen fixed varies widely among species, but I recently discovered that the USDA plants database gives information about the amount fixed about many, many species native and naturalized to the United States. Check out their advanced search page to select species for your area. They classify species as HIGH (160+ lbs/acre), MEDIUM (85-160lbs/acre), and LOW (1-85lbs/acre). Note that there are a few species that might represent data entry errors. For example Phragmites is listed as a nitrogen fixer, though I’ve been unable to find another reference to this being the case.
It’s interesting to note that many of the most hated naturalized species turn out to be incredibly efficient nitrogen fixers. In fact the “high” nitrogen fixtures category is a rogues gallery of successful dispersive species, like Russian olive (Eleagnus angustifolia), kudzu (Pueraria lobata), and Scotch broom (Cytisus scoparius). I decided to use the database to generate lists of native and non-native nitrogen fixers and categorize them by their efficiency.
In many cases there’s a strong temptation to use nitrogen fixing species which are also edible. I’d like to point out that if you harvest a heavy crop from a nitrogen fixer, you’ve probably taken most of the nitrogen with you, though this may not be the case with fruits as much as it is with beans and leaves. This is another good reason to use efficient native nitrogen fixers even if they’re not edible. On the other hand, if what you really need is nitrogen there are very few native species in the “high” category, making a good case for use of white clover and other non-natives.Though not all native plant enthusiasts would believe it, I’ve spent decades promoting underutilized native plants. While you may choose to grow non-native pears and peaches in your food forest, there is no particular reason to grow a non-native nitrogen fixer over a native one, with all things being equal. In fact I tend to assume that native plants have a network of visible and invisible relationships with other organisms of all kingdoms, making them more desirable to use whenever possible. I think with the information these databases have provided, we are in an excellent position to promote particular native nitrogen fixers for use in permaculture projects.
With that said, let’s look at a few tables I put together for different regions of the country and then review some of our top native candidates. The astute reader will note that there are very, very few natives in the “high” category. I would speculate that there may be few anywhere, but that they are spreading around very, very successfully.
I’d like to profile a few of these US native nitrogen fixers that have broad range of applicability.
Red Alder (Alnus rubra) grows throughout much of Western North America, particularly near the coast. It coppices readily, at least if you start when it is young and do it frequently. Unlike most alders it does not require wet feet. It can also handle some partial shade. Here in my garden in Massachusetts is killed the ground during winter and re-sprouts up to 10 feet high the following year. According to the database, this is the only tree native to North America that fixes over 160 pounds of nitrogen per acre per year. Though you might think that other alders are equally powerful, the genus actually shows up in the high, medium, and low categories.
White Prairie Clover (Dalea candida) is a native clover of the prairies that extends some into the Eastern Forest region. It is used to make a tea, but had never crossed my mind as a particularly significantly given at all of the hundreds of species that seemed to grow in the prairie. Now I know that the USDA database states that this is the only herb native to North America that fixes over 160 pounds of nitrogen per acre per year. Though it wants full sun and (and can handle fairly dry soils), I’m going to try to find room for some of this little–used native that is deserving of a place in the spotlight. Interestingly, like alder, members of this genus can be found in the high, medium and low categories.
Buffalo Berry (Shepherdia argentea) it is native from New York through California. It is fairly drought tolerant and suckers extensively. It can produce very high volumes of edible fruit, though you need both male and female plants to get it. It can coppice, though again Jerome Osentowski reports that at his site it does not do so reliably. USDA rates this as a “medium” nitrogen fixer. The related S. canadensis and Elaeagus commutataare also “medium” N-fixers and widely native.
I’d love to hear about your experiments using the database (or this article) to select native nitrogen fixers for your area. Myself, I feel like I have a new tool to make sure that the nitrogen fixers I select will be the best available for the job. I also feel like I can make a strong case for growing some native species that are currently very underutilized.
Today is special for two major reasons. It is a new moon and we’re receiving a much-needed steady rainfall… atlas bringing a halt to the desiccating drought. These rainy days are so pleasant; its a good time to be indoors and bring order to things within. I want to share some recent thoughts about caneberries, brambles, or to be more taxonomically correct— the Rubus genus. Being apart of the Rosaceae family the Rubus genus is a widespread group of plants with species found growing on all continents. Rubus spp. have been used for food and medicine since ancient times and some very prominent fruits like blackberries and raspberries are members of this genera. Most folks are only familiar with black raspberries and the two previously mentioned, but there are many other interesting Rubus species worthy of examination and cultivation. There seems to be a term for just about everything… it turns out there’s even a term for the scientific study of members of the Rubus genus— batology. No, not the study of bats. In exploring batology you’ll find that the most commonly cultivated brambles come from a complex lineage…
Rubus phoenicolasius, or Japanese wineberry, is a species native to Asia that has
naturalized in much of eastern North America. Wineberries are sought after fruits, which like most caneberries, are born on second year canes (floricanes). Apparently the canes can reach 3-6 feet in height and are notorious for spreading quite rampantly. Wineberries are regarded as ‘gourmet raspberries’ and can be processed into jams, jellies, and pies just like regular raspberries. I’ve yet to try fresh wineberries, although last year my friend and colleague, Kevin Brennan, was kind enough to send me a jar of wineberry jelly. Kevin lives on the east coast and loves wineberries. Here is a post he wrote about them a while ago on his blog, The Suburban Trip. Kevin sent an email explaining wineberries and this is what he said:
“The best thing about wineberries is that they are just so abundant. The almost furry berry clusters contain up to 10 berries each and they are super easy to pick in large quantities. I once picked 2 gallons in 15 min. The wineberry produces fruit on 2 and 3 year canes and layers it self and creates large patches. Some spots I go to are in full shade and are still producing a ton a berries, I would really like to try to promote the growth of wineberries in wild gardens for selling to restaurants and farm stands because of the ease of picking. I would like to try saving seed from jelly making and then just throwing them out in slightly tilled areas, or even shitting the seeds like the birds to make patches.”
I love Kevin’s last statement about seed propagation. In fact, he sent me a bag full of seed last year, and I sowed the seeds earlier this spring after a few months of cool-moist stratification in the refrigerator. For a while they didn’t do anything and finally germination occurred. Voilà! No sparse germination either, these babies came up with fury. Now I am potting them up and eventually will plant out my own wineberry patch!
Another Rubus character of particular interest is R. ursinus × idaeus, or boysenberry. This is a complex hybrid which came about as a cross between European raspberry (R. idaeus), common blackberry (R. fruticosus), and loganberry (Rubus × loganobaccus). The hyrbid was originally developed during the late 1920’s in California by a farmer named
Rudolph Boysen. He abandoned his farm and years later the hybrid was found and named by two horticultural explorers and berry enthusiasts, George Darrow and Walter Knot. Now nearly 90 years later boysenberry plants are readily available in the nursery trade. I got my boysenberry from a nursery in Ohio and I’ve been growing it in a container. The plants are trailing and entirely non-erect, so they require a trellis if you intend to keep ’em off the ground. This year my plant has ripened a few handfuls of delicious berries which are best described as a combination of a blackberry and raspberry…with the tart blackberry flavor and more of the raspberry phenotype. Like all caneberries, boysenberries are an etaerio or aggregate fruit containing several drupelets. An aggregate fruit develops from the merging of numerous separate ovaries from one flower. On the contrary, a simple fruit, like a grape, develops from a single ovary.
Amongst the hundreds of caneberries some other obscure ones are thimbleberries, purple flowering raspberries, dewberries, and loganberries. I’d love to hear about your experience growing or harvesting these luscious drupes!