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Care of Newly Planted Trees and Shrubs
Shade trees are important for several reasons. A San Antonio summer would be unbearable if we couldn’t escape to the shade of oaks or other large trees. The trees reduce water use on landscapes and save huge amounts of energy in the form of air conditioning. Trees are attractive and add thousands of dollars to our property values. Trees also can be important for birds and other wildlife.
The best time to plant trees is in the autumn but, with good container-grown stock and the proper care, any time is a suitable time for tree planting. If you plant trees when the weather is hot and dry, you just have to be more careful about mulch and watering. Three to four inches of shredded brush, bark, leaves, pecan shells or compost is essential to protect the roots and maximize the growth rate. Research shows that most newly planted trees grow 40 percent faster with mulch over the roots compared to grass growing up to the trunk. Do not let the mulch rest against the trunk of the plant. All plants benefit from mulch, because, as the mulch breaks down, it provides an excellent growing medium for roots, and acts as a slow release fertilizer. Mulch will also help conserve moisture, moderate soil temperatures, eliminate weeds, and protect the trunk from mechanical injury, especially weed whips and lawn mowers. I would guess that more trees die from string mower girdling in South Texas landscapes than from drought.
When you apply the mulch, put it on in the form of a donut shape. The hole in the middle keeps the trunk in contact with the air.
A full size shade tree should always be planted at least 20 feet from the house, 30 feet is best. Dig a hole as deep as the container and two to three times as wide. It is not necessary to add root stimulator or organic material to the hole. The tree has to survive in native soil eventually and, in some cases, the addition of sand or organic material to the hole contributes to root “drowning”. Right after planting, the roots are limited to the planting hole.
There is always the question of what size tree to purchase and plant. Big trees may provide instant shade but they are expensive and require that large holes be dug. In my experience, a tree with a 1½ to 2½ inch diameter trunk seems to be the best buy. Smaller trees adapt fastest to the transplanting and may actually catch up and pass the size of the bigger transplant within two to three years.
Caring for new transplants
Water is probably the most important element in caring for new trees and shrubs. Since a newly transplanted tree or shrub has not extended its roots into the existing soil, adequate moisture needs to reach the root ball and not necessarily the surrounding subsoil. For the most efficient use of water, construct an earthen dam 4 to 6 inches high around the drip-zone area of the plant after planting. Water will have the ability to collect in this saucer and move slowly down into the planting hole. Runoff will be minimized.
Soil type and the amount of rainfall govern the amount of watering necessary. On most well drained soil, one inch of water per week throughout summer and fall is required to establish and maintain good growth. In sandy soils, as much as two inches of water per week is needed.
Occasionally trees may require support, especially in windy sites, to prevent uprooting and leaning until the roots have had a chance to grow and stabilize that tree. Avoid staking too rigidly. Some trunk flexibility allows the flare at the base of the tree to develop naturally. Inspect staking material regularly for tightness and damage, and remove after one or two years.
Trees and shrubs: establishment problems
It can be frustrating when trees and shrubs fail to establish well. The main symptoms of poor establishment are yellow or brown leaves and shoots dying back. There are steps you can take to remedy the situation, but it is better to try and prevent these problems happening in the first place.
What are establishment problems?
In most cases trees and shrubs will establish well, with no problems as long as root health, weather, soil conditions and the aftercare provided are favorable.
If one or more of these factors are unfavorable, trees and shrubs may fail to establish, often within the first two years after planting.
Symptoms
Although they may show some signs of growth, the foliage of trees and shrubs that are struggling to establish may begin to deteriorate, often in early summer, with leaves turning yellow or brown, shriveling and falling. This can take place over several months or quite suddenly.
Causes and solutions
Insufficient water
- Insufficient watering in the first several (2-5) years after planting is the main cause of poor establishment. Nearby trees, shrubs and hedges can also cast a rain shadow. They also have thirsty wide-ranging roots, leading to greater watering requirements than expected.
Remedy: Water more, and more often until new flush of growth begins.
- Weeds, lawns and other vegetation intercept water before it reaches the roots.
Remedy: Keep a circle at least 4 feet in diameter around the base of the plant that is vegetation free for three years after planting, using hoeing, weedkillers or mulch.
- In hot, dry weather, plants lose moisture very quickly.
Remedy: Cover the bare area around the base of the tree with a mulch of organic matter to help retain moisture and suppress weeds. Thick, coarse organic mulches are ideal, cooling the root systems and improving soil structure over time to create a well aerated but moist area where roots can survive.
Deep planting
- Positioning the tree too deep in the soil can lead to stem rotting and tree failure.
Remedy: Scrape away surplus mulch and/or soil from the case of the trunk. In severe cases of deep planting, the tree may need to be lifted in the autumn and repositioned higher in the soil. When replanting, ensure the first flare of roots sits just below the soil surface, avoiding burying any of the bare stem. Keep mulches clear from the immediate base of all trees and shrubs.
Compacted soil
- Roots fail to grow outwards into the surrounding soil if the soil is compacted or excessively dry from periods of drought.
Remedy: Fork through a ring of soil just to the outer edge of the root ball. Most new root development of trees and shrubs in the UK is out laterally into the surface layers or soil rather than straight down. It is therefore important than the soil in this zone is sufficiently loose and aerated to allow for easy root development. Water slowly and deeply.
Wind rock
- Wind rock of unsecured trees and shrubs can damage roots and lead to water collecting in the ‘socket’ caused by the stem moving at soil level. This can lead to fatal rotting.
Remedy: Staking avoids this, but stakes should be no taller than one-third of the stem height and must be secure. Avoid excessively tight tree ties when securing stems to stakes, prevent rubbing of stems against stakes and ties, and remember to progressively slacken the ties as the stems grow.
Plant nutrition
- Although a lack of nutrients is seldom involved in establishment problems, it is worth applying a nutrient or fertilizer to the leaves (foliar feeding) in order to get some nutrients into the plant, even though its roots are not fully functional.
Remedy: Use special fertilizer formulated for foliar feeding, and spray in overcast weather to avoid scorching the foliage. Make sure to spray the undersides of the leaves as well. Fertilizer top dressings in late winter or early spring are worth trying where other factors are clearly not to blame for poor growth.
Larger specimens
Although larger sized specimen trees and shrubs can be perfect for making instant impact or screening, they are naturally more prone to poor establishment. This is because the root system is invariably undersized compared to the amount of top growth. They will require greater aftercare than smaller plants, especially with attention to watering.
Expect it to take two or even three seasons for specimen trees and shrubs to be fully established.
Watering
Water is the most essential resource that you can give your new plant. Immediately after planting, water slowly but thoroughly to saturate the entire rootball and backfill area – this could take a couple of hours with a slow stream from a hose. Watering eliminates air pockets, rehydrates the plant and provides the water necessary for survival and growth.
Water frequently for the first few weeks, every other day if there’s no rain and you have a well-drained soil. After that, water every 5-7 days if needed, until late fall. Trees from containers dry quickly and need more frequent irrigation for the first several weeks. Apply water right over the original rootball, as well as to the backfilled area, because water from the surrounding soil will not move into the porous potting medium where most of the roots are. Skip watering only if you get more than an inch of rain. Don’t depend on your lawn sprinklers to provide enough water for your new plants.
How much water to apply will depend on plant size, weather, time of year, soil type and drainage. Apply enough water to wet the soil throughout the rooting area. Under good growing conditions, apply about an inch of water each time (just over ½ gallon per square foot of soil surface). While a small shrub may only need a half a gallon, ten gallons may be required for a 2-inch diameter tree.
Applying water slowly so that it soaks in is much better than applying it rapidly with a hose. If you do use a hose, set the nozzle to a shower or gentle spray setting. There are tree bags (Gator bags) or rings that you can purchase and place around your tree that hold several gallons of water and allow it to ooze out slowly through small holes. For larger plantings, drip irrigation or soaker hoses may be worth the investment.
On the other hand, avoid over-watering any plant. This is most likely if you have clay soil and/or underlying poor drainage; in this case, the loosened soil around your newly-planted rootball may fill up like a bathtub and “drown” the roots. If in doubt, do a percolation test before you plant and make sure that water drains from the hole completely within 24 hours. If not, choose a tree suitable for a wet site such as the Montezuma Cypress.
General Spring and Summer Planting and Watering Recommendations
for Tree and Shrub Planting
Planting
- Call 811 One-Call and SAWS 233-2010 for utility locator service before creating site plan. Service is FREE.
- Once utility lines are marked, identify tree-planting locations 10-30 feet from building.
- Dig a hole at least two (2) times the diameter of the root ball, preferably wider.
- Always keep the top of the root ball level or slightly higher than the surrounding grade. Never put soil on top of the root - ball -- only around it.
- Water the root ball and backfill completely. Apply another 7- 9 gallons of water over the entire planting zone.
- Remove all nursery ties, flagging, rope, and tags. Watering
- Ample soil moisture must be maintained throughout the two-year maintenance period. Need for watering can be determined by feeling the soil under the mulch at 3- 6" depth for moisture. (Check twice per week for adequate soil moisture). Lawn sprinkler systems cannot provide thorough watering.
- Follow the 3-2-1 method: start by watering 3 times per week for the first month, 2 times per week for the second month and 1 time per week for the third month. Then water 2 times per month for the next 3 months and 1time per month through the next growing season (March- August).
Mulch
- Mulch must be renewed once a year at 2 inch depth and at a radius of 24- 36 inches from, but not touching, the trunk of each tree for the two-year maintenance period. Proper mulching helps retain water, moderates soil temperature, and can reduce the need for weed control.
Tree Wells
- Tree wells must be kept free of weeds for the two-year maintenance period. This weed-free zone can be accomplished by pulling weeds on a monthly basis.
- Do not use string trimmers within the mulched area around a tree. String trimmers will damage and may kill the tree.
General Fall and Winter Planting and Watering Recommendations
for Tree and Shrub Planting
Planting
- Call 811 One-Call and SAWS 233-2010 for utility locator service before creating site plan. Service is FREE.
- Dig a hole at least two (2) times the diameter of the root ball, preferably wider.
- Always keep the top of the root ball level or slightly higher than the surrounding grade. Never put soil on top of the root ball-- only around it.
- Water the root ball and backfill completely. Apply another 7- 9 gallons of water over the entire planting zone.
- Remove all nursery ties, flagging, rope, and tags.
Watering
- Ample soil moisture must be maintained throughout the two-year maintenance period. Need for watering can be determined by feeling the soil under the mulch at 3 – 6 inch depth for moisture. (Check twice per week for adequate soil moisture). Lawn sprinkler systems cannot provide thorough watering.
- For fall plantings, water 2 times per week for the first month and 1 time per week for the second month. Then water 2 times per month for the next 3 months and 1 time per month through the next growing season (March- August).
Mulch
- Mulch must be renewed once a year at 2 inch depth and at a radius of 24 – 36 inches from, but not touching, the trunk of each tree for the two-year maintenance period. Proper mulching helps retain water, moderates soil temperature, and can reduce the need for weed control.
Tree Wells
- Tree wells must be kept free of weeds for the two-year maintenance period. This weed-free zone can be accomplished by pulling weeds on a monthly basis.
- Do not use string trimmers within the mulched area around a tree. String trimmers will damage and may kill the tree.
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