I’ve finally gotten around to posting the Roots To Fruits 2014 schedule of events! We are psyched to be offering many exciting classes and workshops in the coming year. More information for each event will be posted to the RTF website soon. Stay posted for registration details…
The Member-Written, Quarterly Journal of North American Fruit Explorers (NAFEX)
Vol. XLVI, No. 3, Summer 2013
Fruit Tree Polycultures
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.
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 Podcast with 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 with Lee Reich.
Here are some recent photos of field trips, events, and happenings in the garden…
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.
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.
Comfrey is a plant with a multitude of uses not only in the home apothecary but also in the garden. There are several species in the genus Symphytum, all of which merit special attention, but generally S. officinale, or common comfrey, and a hybrid species S.x uplandicum are most often used. The ladder of which is particularly suitable for the home garden because it is sterile and doesn’t spread by seed. The most available variety is called ‘Bocking 14’. These are upright comfreys which can grow 5′ tall. There are also rhizomatous species which only grow 6″-1′ high and spread to form a dense groundcover.
Comfrey is prized amongst herbalists for its incredible healing powers. Comfrey leaves and roots
contain a high concentration of allatoin– a substance that speeds cell renewal. It got the colloquial name ‘knitbone’ for its use in treating wounds and reducing inflammation from broken bones and sprains. It’s not a surprise that comfrey fulfills a similar ecological niche working to heal wounded and degraded soils. Comfrey is referred to as a mineral accumulator or dynamic accumulator for its ability to mine nutrients with its deep roots (which also loosen compacted soils). Those nutrients are then deposited in the aerial parts of the plant; being especially high in potassium, phosphorus, calcium, and nitrogen. When the aerial parts die back in the fall those nutrients assimilate into the surrounding soil. Gardeners can facilitate this process by intentionally cutting the plant down at strategic times for use as mulch around fruit trees, berry bushes, or in the veg garden. In the permaculture world we
refer to this process as ‘chop-n-drop’. Plant comfrey at the base of your fruit trees and simply chop-n-drop the material right in place; breaking the leaves and stalks into smaller pieces will accelerate decomposition but is not necessary. This is an effective way to build topsoil rapidly and reduce off-site inputs. From my experience I’ve been able to get anywhere from 3-5 cuttings throughout the season. One fella recently told me he cuts his back 7-8 times! I like to wait for the first flush of flowers in early summer because they provide excellent bee fodder.
Another strategy for utilizing comfrey’s amazing mineral accumulating capacity is to brew a fermented comfrey tea. This is a very easy procedure which entails chopping up a few handfuls of comfrey leaves and placing them in a 5 gallon bucket with water. Cover with a lid and let the mixture ferment outdoors for 1-2 weeks. Alternatively, start the batch by pouring boiling water over the plant material and letting it steep for a few hours then adding room temp. water to fill the rest of the bucket. The hot water method seems to extract more of the nutrients. You will know its ready when it has a strong stank…a good stank! Apply with a backpack sprayer diluted or undiluted. This fermented tea can be used a foliar feed or applied directly to the soil.
I grow comfrey around my compost bins and periodically add it to new piles or existing piles to jump-start the decomposition process. I also like to think that the comfrey roots capture any leached nutrients from the compost pile. One reason some people bash on comfrey is because its nearly impossible to get rid of as the tiniest piece of root will put on adventitious buds and sprout into a new plant. Easy to propagate? Ooooh yes! Aside from comfrey’s amazing medicinal qualities and numerous garden uses, it is also a very beautiful plant that can tolerate almost any soil type and will grow well in partial shade. Some ornamental varieties include ‘Goldsmith’, ‘Hidcote Blue’, and ‘Dwarf White’. I would love to hear how you’re utilizing comfrey in your garden! Cheers.
Short video clip: Comfrey Chop-N-Drop Timing