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Newly Grafted Trees

Young grafts should be treated closer to vegetable starts than to trees. A nursery bed for that first year, at least, is required. Although the tree will require different environmental and nutritional needs than an annual, they do need the same sort of babysitting. Consider water and warmth as the “fertilizers” of first importance. This latter point is all to often left out of the equation. This also means keeping the humidity up, especially if the union is not healed so well. (Drying out the scion may not simply kill it, it may be just crummy growth). Also, make sure it is the growing conditions and not the grafting procedure that is causing slow growth. This especially means aftercare for proper heal. When they are growing, give them the attention you would give to your little tomatoes, including mulching and weeding.

There will be a disconnect in how the baby is treated in this first year or two, and how it will receive nutrition as an adult. Later in life in a healthy system, it will do well with gradual release through organic matter, in conjunction with good mycorrhizal fungal connections. Now, in a bed that has been prepared with forethought (fungal connections partially in place) and living soil, good growth is possible. Even in this situation, some supplementation is helpful. A foliar application is great, but a sustainably derived fertilizer in that bed is a good idea as well. They benefit from a bit of nitrogen which, being easily available in a mineralized form is an easy one, as is K. But, P and other micronutrients really should have been developed in that living soil. It is when the quick fix is needed that growers turn to industrial farming methods like triple superphosphate, miracle grow and 20 20 20 .

Having done this quite a bit commercially, I find that that first year never really is all that spectacular for growth, whether that is seedling plants or grafted fruit trees. I think they are pissed from being moved around and violated, and they need to be at peace again. That second year is always awesome, for most. But, if the soil is a mess and it is too late to fix it, foliar sprays, watering on time, and keeping things in the low 70’s will give the best growth rates.

If the little guys are stunted in that first year or two, it will take a few more to get things back on track, in my experience. That said, a small tree is not always a poor tree. (Charlie Brown knew this) As long as it is healthy, slower can also mean denser and more resilient wood. I would put our smaller gritty trees up against the overly succulent fertilizer pushed trees any day of the week.

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Ask the Farmer : Tree Irrigation ?

Do you see many orchards around here choosing to irrigate?

Irrigation of course, can mean a lot of things. What is being asked here I think is whether or not a constructed system is put in place to deliver the water.

Irrigation, as in drip-line, is used for high density dwarf systems. In these arrangements, whether they cultivate or not, it is usually recommended due to the meager root system. Trees using size reduction rootstocks (dwarf), require a good deal more pampering with respect to water. Traditionally this was delivered through open canals, overhead sprinklers, etc. Modern techniques include soil drenching through plastic emitters in miles of plastic tubing. It is an absolute must in many of the dryer regions of the northwest and California, but is popular throughout the country.

In the wet northeast, with standard  trees it is unnecessary. Trees obtaining their natural large stature will have roots mining for water over a very large area. Roots can extend meters down and in circumference at least twice the distance of the canopy. This means resilience during dry spells, and buffering against extreme cold.

Irrigation can confine roots to the pampered area in many cases. If the rooting mass is confined to shallow, smaller areas due to trickle irrigating, later stresses like cold or drought can lead to mortality. The mechanism here (and backed up with numerous studies) is the tendency for roots to amass in areas of ideal culture. That is, where it has good nutrition and soil moisture content. While this is good for the tree in general, it does limit the yardage the roots will occupy. This is pronounced if the outlying area is dry. Roots do not really grow toward ideal soil, they just don’t proliferate where it is poor. An example of the possible danger is when irrigation is confined to a shallow depth by continuous light applications. Roots will be largely clustered in this same shallow zone. In colder areas, this can lead to root damage or death . It can also have such consequences in warmer, dryer areas if there is a pause in irrigating (ie- broken lines or power outages).

Some alternatives include:

  • Increase the organic matter in your soil. Fully composted materials are advised if you are incorporating it directly.
  • Surface application of organic materials. This is the place to put the coarser materials, and higher carbon detritus. If it is a continuous application, we call it mulch. Bark, hay, straw, leaves and wood chips all fit in this category.
  • A 5 gallon pail of water really isn’t all that heavy. At 8 pounds a gallon, that’s 40. One in each hand (filled 4/5 so it doesn’t spill on you) is 64 pounds. That’s all you need to deal with during the occasional drought for your young tree.
  • Grow standard trees. These are those with a natural seedling rootstock that will let a tree grow to its full size. They can be pruned to be less tall and still have a large canopy and extensive root system. Think of this route as raising self sufficient children.

We suggest watering during that planting year, especially during dry spells, for better growth. Sandy soils of course will need more attention than heavier ones. Mulching is a great way to conserve that moisture ( keeping  it away from the trunk) and do it initially after the soil is wet.

Here is something to consider : The US Geological Survey posts on their site that a mature oak can transpire 40,000 gallons of water in a year. That’s one tree. Now, an apple tree is a whole lot smaller than an oak, so in the interest of fair play, let’s reduce that figure 40 times. That leaves us with 1000 gallons for a mature apple. However, if the tree is transpiring that much as water, it must also be absorbing  more to use in metabolic processes. Then there is the issue of delivery versus root uptake. That is, the soil must contain more than this amount of water to begin with. Irrigation through precipitation or human intervention must exceed the volume absorbed by the tree. To make an impact, it would seem a very large volume would have to be delivered indeed.

In conclusion, a plant with a small root system will require a good deal more attention as regards water. This lines up nicely, since a small root system stands the chance of benefitting from the amount of water we are likely to be able to deliver. This is why farms tend to irrigate their high end vegetable plots but not irrigate hay fields and cider orchards.

Water is the single greatest and most overlooked of fertilizers for plants. Time and money are the single greatest commodities of the human being. With proper decisions, nature can do a good deal of the work for us.

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Rootstock Crowding Study

I wanted to bring attention to a study we are doing at Walden Heights. In both research and direct observation, there is evidence that crowding of root systems leads to some dwarfing effects. Apples in particular tend to avoid growing in the same soil regions that other members of their species do. ( Atkinson D, Naylor D, Coldrick GA (1976) The effect of tree spacing on the apple root system. Hortic Res 16: 89-105 ). Additional consideration is that direct competition of many other species in the vicinity should lead to an overall size reduction. By creating a full block planting, roots will be forced to compete 360 degrees.

We have planted two sections to standard stock apple, one as an 8×8 foot grid, one as an 4×8 foot grid. We also, for comparison have standards at 15 x 15, and 30 x 30. We also have apples (part of another test) in a high tunnel at 8 foot spacing. Since we alot of scionwood collection for the nursery, if the fruit production is, well, unfruitful, there is still merit in the exercise. We are forced by necessity since we need to find room for what is closing in on 500 varieties, without resorting to dwarf stock or excessive topworking. It gives us an opportunity to run such a test without risking too much. We will keep everyone posted on the progress. There are about 500 trees in the two blocks, of 6 standard rootstocks and roughly 300 scion varieties.

Obviously precocity isn’t necessarily being addressed, at least at first glance. Since stress often leads to early bearing, who knows. If excessive pruning is needed in the early years, this may actually delay bearing. Our goals here have never been for rushing the crop- thats what berry bushes are for. Tree longevity and low maintenance plants are. If we can couple this with a tree that can more within reach for spraying, harvesting and scion collection, it may have a place in many a farm plan. Not as a replacement, but as an addition to the overall system.