Too Deep in Love: Two Common Killers of Freshly Planted Trees
Trees are the cornerstones of our landscapes. No other kind of plant impacts the local ecosystem as broadly and effectively as trees; they create shady, cool microclimates, provide erosion control with their expansive roots, and supply habitat and food for many creatures. Planting trees is not difficult, but with their slow growth and considerable price, it pays to get it right the first time. Here are two common problems we see with freshly planted trees at Rick’s Nursery.
The most common and fatal error in planting trees is burying the root ball too deep. It only takes a few inches of soil on top of the root ball to smother it. When you plant your tree, take it out of the pot, then lightly brush off the loose soil on top-assume that the tree was never planted at the correct depth in the pot by the nursery that grew it. Then, after you finish planting the tree, you should still be able to see the top of the potting soil. In areas of poor soil drainage, it may be appropriate to leave the “shoulders” of the root ball as much as 2 inches above grade. Top with mulch to prevent the surface roots from drying out, but be careful not to contact the trunk. It will look wildly incorrect when created for the first time, but it is essential to the plant’s health. When you plant too deep, you starve the roots of oxygen, and the tree is prone to dying within the first 2-7 years of planting. Once you start observing trees, you may even begin to notice mature ones that are planted too deeply; trees should never look like a telephone pole sticking out of the ground, there should always be a distinct root flare. If you have already planted your tree too deep, you can carefully excavate by hand around the root flare to expose it. You can even mitigate too-deep planting in mature trees, though care should be taken not to damage roots. Just carefully remove the soil until you find the root flare, then mulch.
Our soil in most parts of Colorado is notoriously poor. Whether you have sand, clay, or just decomposed granite on bedrock, amending your soil with organic matter can solve several soil problems. We often forget, however, that in life and gardening, moderation is key. When you amend the backfill of your planting hole, you should use a maximum ratio of 1 part compost to 4 parts native soil. When you amend by more than 20% organic matter, you risk “containerising the hole.” This happens when you over-prepare the backfill of your planting hole; the roots of your tree are content with the fluffy, rich soil, and never establish outside the new hole. This creates circling roots and other problems associated with container trees, thus “containerising the hole.” Trees whose soil is over-amended are more prone to overwatering because the soil holds on to excess moisture. Trees may also begin to sink and list to one side as the extra compost decomposes and shrinks in volume, especially when the compost is dug under the root ball. Thus, the bottom of your planting hole should always be firm, unamended soil. Fresh compost should never contact the roots directly and should be mixed thoroughly into the backfill soil. Depending on what kind of tree, and the soil condition, it might be wisest to skip amendment altogether, and just let the wood mulch on top do the soil work. Generally, though, just a dab of compost will do the trick. Ultimately, we gardeners see soil amendment as an act of caring; just make sure not to love your tree to death.
Nothing makes us happier at Rick’s Garden Center than seeing your nursery plants thrive. For more information on planting, see our Tree and Shrub Planting Guide, available on our website. Happy planting!
Tree and Shrub Planting Guide
Tree & Shrub Planting Guide
Call before you dig! Dial 811
1. Measure the depth of the root ball. Your planting hole should be approximately one inch less in depth than the root ball itself (Example: 14” root ball should be planted in a 13” deep hole). Lay your rake or shovel handle across the hole, the root ball should be just slightly higher than the handle. The tree should sit on undisturbed, firm, soil. You need a firm foundation so the tree doesn’t settle after it is planted.
2. Dig a large saucer shaped hole approximately 3 times the diameter of the root ball (Example: the root ball is 16” across, the diameter of the hole should be 48”). The saucer shaped sides of the planting hole help the new root growth to move outward and upward, away from the trunk or crown. This helps prevent the new roots from girdling the trunk and maintains proper oxygen and nutrient flow to the root system.
3. Gently remove container, for large trees or shrubs, it may be easier to cut the container off. DO NOT pick up the tree or shrub by its trunk and attempt to “shake” off the container.
4. Check the root ball for roots that are growing in a circular pattern. If the roots are “Pot Bound” it is recommended to shave off an inch to an inch and a half of the exterior of the root ball. Use a hand saw to slice off strips from the exterior of the root ball around the perimeter. Prune any remaining circling roots. This has been found to be more effective than vertical slices through the root ball and prevents root girdling of the tree. Do this in several sections around the root ball. This will stimulate the roots to begin growing out of their circulating pattern.
5. Dust the root ball and cut root ends with a mycorrhizae inoculant, such as Mykes, Soil Moist or other product, so that there is good contact with the root system per the product directions. If possible, dampen the root ball to help adhere the dust to the root ball.
6. Place the tree in the hole and backfill with the original soil, remove any large dirt clumps or rocks. Water in the soil to settle it down, do not tamp down. Continue backfilling up to the top of the root ball. If you have any excess soil, use it to build a raised berm around the outside of the hole. This will aid in proper watering. NOTE: If you have heavy clay soil, consult our Nursery Manager. It is NOT recommended to try and adapt trees to soil they cannot tolerate.
7. Mix the Ferti-lome Root Stimulator or Bonide Root & Grow according to the directions on the label. Water the tree or shrub thoroughly with the mixture throughout the first two growing seasons.
8. Add mulch to the planting area, keeping the mulch 4-6 inches from the trunk of the tree or crown of the shrub. This will help retain moisture, moderate the soil temperature and prevent mower/trimmer damage, ensuring a good consistent growing area for your new plant. It looks great too!
9. Large, tall trees will require staking and guying. This will prevent any wind damage that could topple or shift your tree causing severe root damage. Tree straps should be loose to allow the tree to move a little in the wind. Remove tree straps after one year.
TREE WRAP We highly recommend using tree wrap on any smooth barked /and/ or dark colored tree trunks. Winter sun can cause frost cracking in young trees, especially trees with southwest exposures. Wrapping should be applied around Thanksgiving and removed by April Fools Day or Easter.
TRUNK BARK PROTECTORS The only trees that may not need Deer Guards are those planted behind a 6’ fence that the deer can’t see through; or have thick rough bark! It is never worth risking the damage that deer WILL do! This can also protect against mechanical damage from mowers.
Newly planted trees will need 5-10 gallons of water a week for the first two years until they are established. It is better to water more deeply and infrequently than lightly and frequently. If the soil is still wet a couple of inches down around the root ball, avoid watering.
Don’t forget to Winter Water!! Trees still lose moisture during the dormant period. If there has been no measurable precipitation for over a week and temperatures are above freezing, water lightly once a week, 2-3 gallons. This goes a long way to preventing winter dye-back and root damage!