National Arbor Day is Friday, April 29. This year marks the 150th anniversary of the tree planter’s holiday. National Arbor Day is always celebrated on the last Friday in April, but many states observe Arbor Day on different dates throughout the year based on best tree planting times in their area. California’s Arbor Day was March 7 to 14—but it’s not too late to plant a tree in honor of National Arbor Day.
Please do plant a tree for Arbor Day—but make sure you do it right! The success of a new tree depends a great deal on how it is planted. We’ve all witnessed trees that just never seem to thrive. Frequently this is caused by a poor planting or staking job.
Purchasing the tree – A 15-gallon container tree is a good size to plant in the landscape, if you are doing it yourself. Look for trees with a central leader and side branches that are evenly distributed around the tree. Not all trees will have a central leader, but you still want to avoid trees whose side branches all arise from the same point, as these will become a lot more work as they grow. Try to pick a tree that does not need staking (read below).
Preparing the planting hole – The planting hole need only be as deep as the root ball. Plant “high” in all but extremely sandy soils. The root ball should set on a firm base with the center slightly higher than the edge of the hole. Don’t plant any tree so low that water flows towards the trunk. While the hole should be only as deep as the root ball, the width of the hole should be at least twice as wide as the root ball.
Setting the tree
- Orient the tree to give the most pleasing landscape effect.
- Place the side with the most branches into the prevailing wind direction.
- If wind, sunburn, and appearance are not problems, place the largest branch or heavy side of the tree towards the northeast. The less developed side of the tree will be favored with more light from the southwest.
- Back fill the hole with the original soil. Organic amendments are only necessary for extremely heavy clay or sandy soils (mix 20% to 40% organic matter by volume, with the back fill soil). Work the soil around the roots so that they are spreading and supported by soil. Firmly tamp down the soil with your foot several times while backfilling. Contrary to popular belief, fertilizer is not a necessary requirement at planting.
Watering – Tree water basins should be 3 to 4 feet in diameter for a 15-gallon tree. Fill with water to settle the soil and provide water to roots. If trees are planted in lawns, remove the grass so you have a 3- to 4-foot ring around the trunks, and fill with decorative rocks or bark (keeping the bark from touching the trunk). Young trees are stunted by grass growing close even when additional water and fertilizer are applied and are prone to injury by lawnmowers and weed whackers.
Staking – Trees are usually purchased with a wooden stake bound tightly to the trunk. Remove it. This nursery stake is only for ease of nursery operations and will hurt the proper development of a tree in the landscape. Try not to stake your tree. Staking trees is undesirable, but sometimes necessary. Support staking may be required when a trunk is not sturdy enough to support the top or it is unable to return to an upright position after a wind. Take the time to plant and stake a tree correctly.
How not to stake a tree – If staking is necessary, plant the stakes with the tree. Use two or three support stakes and loosely tie the trunk to them with wide rubber ties. Hold the trunk at the base in one hand and slide your hand up until the top is upright…this is the height to attach the ties.
Stake removal – Most stakes can be removed after one year. The sooner a tree can stand alone, the sooner it will become strong. You’ll notice adolescent and mature trees all over town with wooden stakes still at their sides. These stakes have long since served their purpose and often damage the tree. Needless to say “trees on crutches” look absolutely ridiculous! Remove tree stakes as soon as possible.
What tree to plant – The Master Gardeners have developed a complete list of deciduous, evergreen, and problem trees for our area. You can access it online at tinyurl.com/4w4xrm4j.
The Master Gardeners will be live to answer your questions on Saturday, April 2, 9:30 a.m. to 3:30 p.m. at the Main Street Jamboree at Mooney Grove Park in Visalia; and 10 a.m. to 2 p.m. at the Tulare Garden Festival at Tulare City Public Library. You can also contact them at 559-684-3325, or visit their web site at ucanr.edu/sites/UC_Master_Gardeners.