On the fifth day of winter
a dear friend gave to me
five days of rain.
We’d like to plant a few trees. When is the best time?
Containerized trees may be installed at this time of year by managing root available air and water. In well drained, sandy soils, dig hole slightly shallower than root ball and twice as wide. Root ball will settle as media decomposes. In compact or poorly drained sites, plant 2-3 inches above grade.
Deep planting is linked to premature decline. Use back fill to refill hole. If using bagged soil/topsoil/manures/et cetera thoroughly blend at 60/40 ratio. 60% or more native soils with 40% or less bagged manure/peat/compost. Break up clumps and loosen sides of hole.
More than a “finishing touch,” mulch outside the root ball helps reduce weed competition. Prevent soil compaction with a 2-3 inch organic mulch layer to the drip-line.
Correct root defects for stability and tree health.
Ideally, roots radiate from the trunk, extending out into the landscape. ‘Shaving’ the periphery with sharp knife, scissors or shovel is appropriate if roots bear the imprint of the container. If they are circling, trim deflected roots where they bend. New, regenerated roots will radiate away from trunk.
Stem girdling roots restrict nutrients and water to that portion of the tree. Remove stem girdling roots at the point of origin to reduce likelihood of tree decline.
Water is the best amendment.
Temperature, cloud cover, wind, soil characteristics and season of planting play a role in how much water is needed. Apply water to the root ball and slowly enough that it is able to soak into roots. Research at the University of Florida indicates consistent irrigation is more beneficial than large volumes of water applied inconsistently. Manage root available air and water with proper irrigation and not planting too deeply.
In sandy well drained soils, apply a gallon of water per inch of caliper. Daily, for two weeks. Every other day for two months. Weekly until established. Rainfall is an excellent substitution for irrigation. Half an inch of rainfall will percolate to a depth of six inches. Do not water saturated soils.
So what is caliper?
Caliper is a measurement of trunk thickness at twelve inces above root. A 1.5” caliper tree means that the trunk is 1.5” across. Larger nursery stock requires more water per irrigation event and for longer duration. Nursery stock at 2-4 inch caliper would need daily irrigation for a month. Every other day for 3 months and weekly until established.
Should I put fertilizer in the hole?
We want to give trees a good start by providing everything they need. However current recommendation is not to place fertilizer in the hole or fertilize at planting. Fertilizer rates, timing and formula vary by species.
Staking is temporary.
Not all trees require staking. Loosen and re-position straps to prevent girdling stems. Allow the trunk to move slightly. This is an excellent publication by Ed Gilman and Laura Sadowski with tree planting practices and illustrations. Best wishes for good success. Call or comment below with questions. Happy Gardening!