Our Beloved Summer Saviours – Shade TreesPosted on : July 5, 2018
Selecting a tree for your home or work space is like selecting a pair of shoes; you want to make sure it fits, has the desired shape, leaf type, fall color and flowers, if desired.
Trees are grouped in small, medium, or large categories and knowing the mature (full grown) height and spread is critical in making the best selection. TIP: A tree’s feeder roots always extend at least 10 feet past the drip line of the tree (tips of the tree branches) so use this information to determine best variety for your spot.
When creating a tree planting plan, it is much better to plant 5, 10, or 15 gallon trees because the roots will become established in two seasons (with good care) Smaller, younger trees are like small children; they have lots of juvenile hormones and are more vigorous than trees grown in 30, 45, or 65 gallon containers. Large older trees do not establish quickly and can take several years to “root-in” and this translates as you being the nursemaid hand-watering these trees until they become established. Smaller trees are easier to handle, more economical, and respond to the environment quicker.
In selecting your trees from the nursery, make sure they are healthy, strong and straight. Inspect the trunks and branches to make sure there are no cankers (like the ones we get in the mouth) on the bark or the trunk as this is an indication of a sick tree. Also inspect the trunk for unnatural cracks and bark falling off the tree, because without the bark there will be no flow of water and nutrients to the top of the tree and that side of the tree will not thrive and eventually die.
REASONS TO PLANT TREES
- Summer Shade/ Winter Sun – tree selection should be a deciduous tree (loses leaves in winter) because Houston is one of the 16 cloudiest cities in the winter and we want to enjoy the sun when it appears. Planting for summer shade normally is in the western exposure, but morning sun in the east can be just as brutal. Sun: Schumard Red Oak or Black Gum
- Create a Privacy Screen – this group of trees would be evergreen and are slower growers than deciduous trees. An alternative would be a large evergreen shrub that provides 10-15 feet of height for privacy and shrubs are branched to the ground. NOTE: Shrubs are faster growing than evergreen trees. Shade: Viburnum ‘Awabuki’, Japanese Yew/ Sun: Pineapple Guava, Olive Tree
- Flowering tree – Need to determine do you have a sunny spot more than 6 hours direct sun or shady spot less than 6 hours of sun. Shade: Japanese Magnolia/ Sun: Chinese Fringe Tree
PLANTING A TREE (DEALING WITH CLAY SOILS)
- Dig your hole twice as wide and twice the depth of the root ball. Remove the soil from the hole and put in a wheelbarrow or tub, this makes mixing easier.
- Chop up clay in the bottom of the hole and add 1/3 of a 40# bag of expanded shale and 1# (think coffee can) of Arbor Gate blend and mix with native soil and shale.
- The soil in the wheelbarrow should be chopped up and blended with more shale and another pound of organic fertilizer
- Cut or score the roots if the root ball is pot bound. (You don’t see any soil in the root ball.)
- Cut 1-2 inches off the bottom (looks like a Frisbee) and slice the sides of the root ball in quarters from top of the root ball to the bottom with a serrated knife or pruning saw. If the root ball is not pot bound, don’t prune at all.
- Pruning a pot bound root system stimulates new roots that actively start growing once put into the ground. I also like to prune the top edge of the root ball (bevel/rounding) to reduce the possibility of the root ball drying out if exposed to the air as we plant trees 2-4” higher than the existing grade.
- For proper placement, lay your shovel across the hole to determine how high to raise the root ball. You want the space where the trunk and the soil meet above the shovel handle. Backfill around the root ball with the blended soil and gently tuck in.
- When backfilling the mixed soil, do not pack the soil as this pushes out the air spaces and reduces water percolation of soil. Gently tuck soil around the root ball and build up the reservoir/berm at the edge of the tree well.
- Dig out and remove grass from around the tree at least 4 feet across on a 5 gallon and 6-8 feet on a 10-15 gallon tree. Mulch with pine needles or pine bark mulch and please DO NOT USE DYED RED MULCH (ground up pallets) OR BLACK MULCH (ash is added to make it black and look like humus) but these mulches are like fast food, no nutrition here only death and disease!
- Create a 4-6 inch wide berm (mound) of soil just inside the grass ring to hold water and nutrients when you hand water the tree. This also acts as a reservoir when it rains; the rainwater is captured and directed to the root zone! Also keeps weed eaters away from the trunk. This planting will have a concave (inverted) reservoir not something that looks like a volcano!
- Do not remove the lower branches of evergreen Magnolias; the wound never heals leaving it open for rot, bacteria, and insects. Healthy trees have their branches all way to the ground.
- Wet Areas – even in wet areas, it is advisable to work expanded shale deep into the soil to create air spaces for the roots to grow and breathe.
PLANTING IS DONE – NOW WHAT??
Do not depend on irrigation systems to water in a newly planted tree. Hand watering with a hose at least 3 to 4 times a week will help your fertilizer, soil, and shale “marry” to create the perfect growing environment for your new tree.
So come out to the Arbor Gate and let us help you select just the right tree for your landscape!
Written by Linda Gay
Linda received her Associates Degree in Horticulture from Trident Technical College in Charleston, SC. She moved to Houston the summer of 1979 and worked in the commercial green industry until 1985. October 1985 Linda stared at Mercer Arboretum and Botanic Gardens and retired in May 2011. She was the director for 11 years. Linda is first and foremost a gardener, constantly manipulating soils and putting new plants in the garden, always learning and growing. She has killed plants every which way you can and this experience has made me a plant expert. After 6 months of retirement Linda was very fortuitous and landed in the coolest gardener’s paradise, The Arbor Gate in Tomball, Texas.