When is the best time to plant a tree?

Drought can be hard on trees and the semi-arid dryness of the High Plains is a primary reason more trees were not naturally found here. Here is a link to a recently updated publication from the Nebraska Forest Service trees and drought including advice on watering trees: https://nfs.unl.edu/publications/watering-trees.

Something that can help with drought tolerance is fall planting of deciduous trees. Our experience over the years is that fall planted trees need significantly less watering the following spring and summer than spring planted trees. The winter months typically allow the root systems of such trees to get a foothold so that they are more water efficient the following spring. In Waverly where I live, I’m just now starting to water trees planted last fall, but we’ve been watering the trees and shrubs planted this spring every few days. That doesn’t mean spring is a bad time to plant, it just means such plants will require more watering attention during dry periods. And it also doesn’t mean that fall planted trees don’t need watering the following year. When drought comes, almost all young trees need water.  Be prepared!

Mulching is also a very good thing to help young trees through drought. A 3-4” layer of wood mulch helps shade the soil, keeping it cooler and preserving more soil moisture. The mulch also helps rain or irrigation water soak into the ground without running off. On top of those benefits, mulch helps reduce weed pressure and will assist in the soil becoming more organic, which also helps retain moisture and is healthier for trees. If possible, use mulch from local tree trimmings or other sources to help with recycling efforts (don’t use cypress mulch trucked here from the southeast US!). Of course too much mulch is not a good thing and we regularly see mulch piled up year after year, more or less changing the soil grade around trees, and/or smothering trunks. With mulch, a little bit, reapplied every few years, goes a long way.

Tree Watering & Mulching

• https://hnr.k-state.edu/extension/info-center/newsletters/index.html
• Tree Planting for Success

Watering Newly Planted Trees and Shrubs     

Newly planted trees have not established the extensive root system needed to absorb enough water during hot, dry, windy summers. Even trees two or three years old should receive special care. 

Deep, infrequent watering and mulching can help trees become established. Newly transplanted trees need at least 10 gallons of water per week, and on sandy soils they will need that much applied twice a week. The secret is getting that water to soak deeply into the soil, so it evaporates more slowly and is available to the tree's roots longer. One way to do this is to drill a 1/8" hole in the side of a 5-gallon bucket and fill it with water. The hole should be near the bottom of the bucket.  Let the water dribble out slowly next to the tree. Refill the bucket once after moving it to the opposite side of the tree.  After this bucket empties, you have applied 10 gallons. Very large transplanted trees and trees that were transplanted two to three years ago will require more water.

  A perforated soaker hose or drip irrigation can be used to water a newly established bed or foundation planting. In sunbaked soil, you may need to rough up the surface with a hoe or tiller to get water to infiltrate easily. It may be helpful to set the kitchen oven timer, so you remember to move the hose or shut off the faucet. If you are seeing surface runoff, reduce the flow, or build a berm with at least a 4-foot  diameter around the base of the tree to allow the water to percolate down through the soil, instead of spreading out.

 Regardless of method used, soil should be wet at least 12 inches deep. Use a metal rod, wooden dowel, electric fence post or something similar to check depth. Dry soil is much harder to push through than wet.

Watering Fruit Plants During the Summer

When temperatures exceed 90 degrees F, fruit plants lose water quickly. When this happens, moisture is withdrawn from the fruit to supply the tree. Stress from high temperatures, along with a moisture deficit in the root environment, may cause fruit to drop or fail to increase in size. The stress may also reduce the development of fruit buds for next year's fruit crop. 

If you have fruit plants such as trees, vines, canes, and such, check soil moisture at the roots. Insert a pointed metal or wood probe such as a wooden dowel, piece of rebar or a electric fence post to check the depth of watering.  Even a long screwdriver works well for this. Push these into the soil with the goal of reaching 8 to 12 inches.  This may not be possible if the soil is hard and dry.  If you cannot reach the recommended depth, the plants should be irrigated to prevent drooping and promote fruit enlargement. Water can be added to the soil using sprinklers, soaker hose, drip irrigation, or even a small trickle of water running from the hose for a few hours. The amount of time you irrigate should depend upon the size of plants and the volume of water you are applying. Add enough moisture so you can easily penetrate the soil in the root area to the recommended depth. When hot, dry weather continues, continue to check soil moisture at least once a week.

Strawberries have a shallow root system and may need to be watered more often – maybe twice a week during extreme weather. Also, newly planted fruit trees sited on sandy soils may also need water twice a week. (Ward Upham)

Wood Chips As Mulch

With many municipalities and tree service companies having wood chippers now, gardeners often are able to get chips free. 

Some people have heard that these chips will tie up nitrogen so that the garden plants won't grow as well. If wood chips are used as a mulch, there is no cause for concern. However, if the chips are mixed with the soil, there can be a problem during the breakdown process. The microorganisms that break down the chips need a certain amount of nitrogen during the process. With most green material, there is enough nitrogen in the material itself to meet the needs of the microorganisms.  However, nitrogen levels in wood chips are so low, the microorganisms must borrow it from the surrounding soil. This results in less nitrogen being available to the plants. However, when the raw organic material has been digested, the microorganisms die and release the nitrogen. Therefore, the nitrogen is not lost but is simply unavailable for plant use for a period of time. Again, this is only a concern if the wood chips are mixed into the soil. There is no problem with nitrogen tie-up if the chips are used as a mulch. 

However, one point should be kept in mind. These chips can be used by foraging termites as a bridge to homes and other structures. Termites are light and heat sensitive and will not bother the chips themselves if they are 3 inches deep or less. Therefore, watch the depth of these chips near the house or other buildings.  Also leave a bare area several inches wide next to the house so that any termite activity is noticeable.