I am in the process of putting in a food forest on 7 acres in southern Colorado. I completed my first of three years of mass tree plantings and now is the time to count up the winners and losers, so I can buy better
trees and varieties that work for my
local conditions.
So, what are those local conditions? Elevation 6200 ft. Hardiness zone 6a. Average annual precipitation 16 inches. There are high winds during the spring and fall. Soil is clay loam and is alkaline 7.5-8.0. Biome is pinyon-juniper forest with a scattering of shrubs - three leaf sumac, wax currant, and gambel oak. There is an ephemeral stream bed with new mexico locust, siberian elm and russian olive. The predominant grass is grama, and there are prickly pears and cholla cactus. If there are any more questions about the area, then please let me know.
Onto the trees - I planted nanking cherry, service berry, buffaloberry,
black locust, curl leaf mahogany, sand cherry, burr oak, hackberry, wolfberry, and texas red oak. All plants were bareroot and planted within 24 hours of receipt. Each tree received a generous mulching, a plastic tree sleeve, a shot of 3-4 gallons of
water (inoculated with
compost tea and mycorrhizae), and was planted in the bottom (basin) of a small
swale. The planting took place from April to November of 2021. Sources of trees were the Colorado Forestry Service (CFS), New Mexico Forestry Service (NMFS), and Cold Stream Farms.
The stats in order of survival
Nanking Cherry- prunus tomentosa
Survivability: 19/25 76%
Source: CFS
Discussion: okay some of these were close to the house and I watered them, however, the unwatered plants survived at the same rate, they were just smaller. I anticipate getting fruit from these next year. I'll be buying more of these.
Sand Cherry - prunus beseyii
Survivability: 19/25 76%
Source: Cold Stream
Discussion: This is the true winner, these guys are in a blasted area with dust and cactus surrounding them, and they have not just survived, but thrived. They are growing vigorously. I'll be eating these guys next year. If they taste alright, then I'll order more.
Burr Oak - quercus macrocarpa
Survivability: 15/25 60%
Source: Cold Stream
Discussion: I am inordinately happy with these. They are in the highest, windiest, and sunniest place and they have survived. They don't look happy, but as their taproot grows, and the ground rehydrates from the swales, I know these will hit their stride. Just got to wait 30-40 years to eat the acorns.
Serviceberry - Amelanchier alnifolia
Survivability - 16/35 46%
Source: Cold Stream
Discussion: This is another tree I am excited about. These actually produce a berry that can be eaten fresh, the
chickens love the leaves (that might be why some didn't make it), and they are thorn free. I planted them under established russian olives, and new mexico locust, and then performed a generous chop and drop. I am ordering 100 more. Keep in mind that if you are in a similar climate, then you need to get the alnifolia or utahensis variety. The other varieties are for humid areas.
Buffalo Berry - Shepherdia argentea
Survivability: 13/30 43%
Source: CFS
Discussion: I am somewhat disappointed with these bushes. I thought they would be tougher than the cherries, given their nitrogen fixation, drought tolerance, light foliage, and thorns, but it's... not and I don't know why. Any suggestions? I am going to plant 10 more from Burnt Ridge Nursery, so this will get another shot.
Hackberry - Celtis occidentalis
Survivability: 10/25 40%
Source: Cold Streams
Discussion: Another tree that I had high hopes for. The only survivors were in sheltered areas with shade and wind break, or received high amounts of run off. Secondly, I planted another 25 this spring from the CFS, and NONE have survived or even leafed out. I am not gambling with this tree anymore.
Black Locust - Robinia Pseudoacacia
Survivability: 7/25 28%
Source: Cold Streams
Discussion: Don't be too hard on the black locust. It was planted in November in the middle of a three month drought. I have planted another 10 or so, started from seed. Let's see how they do. I am not ruling out black locust at this time, though I am trialing it against honeylocust, buffalo berry, siberian
pea shrub, and new mexico locust to see what will be my mainstay nitrogen fixer.
Curl Leaf Mahogany (AKA desert mahogany) - Cercocarpus ledifolius
Survivability: 12/49 25%
Source: NMFS
Discussion: I planted these as a hedge, so they are not on contour or in a swale. They also had full sun and no wind protection. They also were not tree sleeved due to their bush habit, and also because I didn't want to alert my neighbor that a living hedge was coming up (sleeves are highly visible). Due to these conditions, I still think this is a worthwhile plant and worth another shot.
Torrey's Wolfberry - Lycium torreyi
Survivability 2/49 4%
Source: NMFS
Discussion: The lesson here is don't push hardiness zones. Wolfberry is zone 7 and I am zone 6. A cold adapted plant can survive heat, but a tropical/desert plant will not survive sub zero temperatures.
Texas Red Oak - Quercus buckleyi
Survivability: 0/49 0%
Source: NMFS
Discussion: Again... don't push hardiness. Global warming ain't that bad yet.
Honorable mention: Gojiberry. I didn't track it's percentages and I didn't plant very many, but I would eyeball its survival at 60%.
Lessons learned: I can't say why, but my conditions favor the prunus family. Another factor was the timing of planting. Spring and summer plantings did far better than fall or winter plantings, and this is due to Colorado's monsoon cycle. So, this advice would hold for the American South west or another region under a monsoon regime. Secondly, you
should respect and double check hardiness requirements before you buy plants. Finally, tree sleeves are essential. They block
deer and
rabbits. No plant can STUN its way out of a deer's mouth. The sleeves also provide a measure of wind and UV protection which is essential in a high elevation environment. The sleeves are a one time investment, and work passively once put into place. They are worth the money. If you can't get tree sleeves then get brush and build stick cages around your saplings.
Next year, I will trial beaked hazelnut,
honey locust, siberian pea shrub, new mexico locust, false indigo, black hawthorn, wax currant, and golden currant. After that, I will try manchurian apricot, elderberry, aronia, mountain mahogany, osage orange, new mexico olive, quince, salmonberry, and ceanothus.
9
