Soil amendments for white spruce

[sachsmo]

Hello,

I have a wind block hedge of 33 white spruce trees 12.5 feet apart. I started this 4 years ago with 24"-30" tall b&b from a local nursury. They seem to be growing very slowly and some are losing some lower branch spread. I think the soil ph is too high, and would like to lower the ph. Is there a good method to achieve this?

 

[kennertree]

Test the soil before you do anything. Are the trees planted at the proper depth?

 

[sachsmo]

I planted them a little high, about 2-3 inches of the root ball above grade. I also mulch them yearly with leaf compost. The nursery I bought them from said to "be lazy when digging the holes". He said too deep and they would die for sure. The soil in my area is ~ 7 ph and is quite heavy clay.

 

[sachsmo]

here's a pic of some,

 

[treeseer]

A closer-up picture would be good. Make sure you can find the flare, as this ISA doc points out:

# Dig a shallow, broad planting hole. Make the hole wide, as much as three times the diameter of the root ball but only as deep as the root ball. It is important to make the hole wide because the roots on the newly establishing tree must push through surrounding soil in order to establish. On most planting sites in new developments, the existing soils have been compacted and are unsuitable for healthy root growth. Breaking up the soil in a large area around the tree provides the newly emerging roots room to expand into loose soil to hasten establishment.

# Identify the trunk flare.
The trunk flare is where the roots spread at the base of the tree. This point should be partially visible after the tree has been planted (see diagram). If the trunk flare is not partially visible, you may have to remove some soil from the top of the root ball. Find it so you can determine how deep the hole needs to be for proper planting.
# Remove tree container for containerized trees. Carefully cutting down the sides of the container may make this easier. Inspect the root ball for circling roots and cut or remove them. Expose the trunk flare, if necessary.
# Place the tree at the proper height. Before placing the tree in the hole, check to see that the hole has been dug to the proper depth’Äîand no more. The majority of the roots on the newly planted tree will develop in the top 12 inches of soil. If the tree is planted too deeply, new roots will have difficulty developing because of a lack of oxygen. It is better to plant the tree a little high, 2 to 3 inches above the base of the trunk flare, than to plant it at or below the original growing level. This planting level will allow for some settling (see diagram). To avoid damage when setting the tree in the hole, always lift the tree by the root ball and never by the trunk.
# Straighten the tree in the hole. Before you begin backfilling, have someone view the tree from several directions to confirm that the tree is straight. Once you begin backfilling, it is difficult to reposition the tree.
# Fill the hole gently but firmly. Fill the hole about one-third full and gently but firmly pack the soil around the base of the root ball. Then, if the root ball is wrapped, cut and remove any fabric, plastic, string, and wire from around the trunk and root ball to facilitate growth (see diagram). Be careful not to damage the trunk or roots in the process.

If depth is right, next kill the grass between the trees and break up that ground. White pines HATE poor drainage.

 

[S Mc]

Mobetter, do you know what cultivar you got? Whereas the species is rated as a "medium" rate grower, many of the cultivars are slow to very slow.

Also, I agree with the others in asking about the planting. B&B plants typically will have the dirt piled up against the trunk and can be many inches above the root flare. So even with planting the root ball high there could still be dirt piled up on the tree trunk.

Once you have established the exposure of the trunk flare, I would increase the size of the mulch rings around the trees to beyond the drip line. We recommend whole tree chips. Mulching will help improve the soil structure and neutralize the pH over time without any other amendments.

I am also curious as to how much herbicide and fertilizer is used in your area with such a wide expanse of lush green lawn and field.


Sylvia

P.S. Just took another look at your photo and, of course, the little guys closer to the great big trees are going to be influenced by any shade cast. White spruce are more shade tolerant than some conifers but definitely prefer full sun.

 

[(WLL)]

a shallow planted tree will have a good strong deep root system if your trees are in good health

 

[sachsmo]

Mulching with wood chips would be better than leaf compost? We have a local compost site with both leaf compost as well as wood chips. I will try the wood chips this spring. Here is a pic of the flare,(or lack of same). The neighboring farmer always turns off his sprayer when passing my little trees, I am sure there is little herbicide damage from the ajoining field. I will need to check on the cultivar type, I was just told it is white spruce, with a few Wallys world Colorado spruces mixed in. Thanks for the tips, Mo

 

[S Mc]

We like whole tree chips because they have all the components a tree has to offer, not just what is in the leaf. Precomposted leaf matter will have even less to offer. Adding mulch will help neutralize soil pH all by itself while decomposing, so is another good reason to use it. I don't see a chlorotic condition from this photo and the tree is holding its needles well, which is a good sign.

I would expose the root flare (or down to the first major roots). Being buried too deep could be slowing them down but the species itself is not very fast growing. I like how you do not have the grass growing right under the tree; good for you. Do be careful when applying the mulch to not pile it against the trunk, thereby creating the exact scenario you are trying to avoid with planting high.

I would encourage you not to get impatient and start fertilizing. If you are supplying appropriate amount of water (and it appears you are), they are not harmed by herbicides (and I didn't see signs of that) the next step is, as said, to expose the root flare.

Sylvia