I have 10 emerald green arborvitaes of 12 ft in height which were planted in spring of 2001. They were bright green until this past summer where in Rye, New York we experienced a drought problem and they started to brown. Even with all the water we recently gotten, they still don't look healthy. I'm planning to retransplant them to a anothert location for esthetic reasons but I'm afraid that they may not survive. Can you let me know what I can do to improve the conditions of the trees and if its possible I can retransplant them and what kind of soil and fertilizer do I need to do this.
Your advice will be greatly appreciated.
Arborvitae  |
It is best to plant the trees directly in the type of soil you have in your yard or garden. It is a mistake to dig a hole and fill it with soil that has a different soil structure, as well as a mistake to spread a layer of soil with different structural texture over the existing layer of soil. These methods create problems with water moving through the soil, and the trees will surely do poorly, if they survive at all. The first thing to do is remove the topsoil from a three foot in diameter circle for each tree and set it to the side. Loosen the subsoil with a spade to a depth of about 2 feet and chop it up finely so as there are no large lumps. Mix a little loam soil, peat moss, sharp sand and bone meal into this subsoil layer to improve drainage and texture. (You may have to get rid of a few shovels full of this subsoil before mixing in the ingredients, or you'll end up with too much soil upon completion). After doing this, return the topsoil (even if is clayey) and thoroughly mix in some loam soil, more peat moss (a layer that is at least 3 or 4 inches thick when spread over the soils surface), sharp sand (unless of course your soil is very sandy or gravelly, in which case omitt the sand), and a cupfull of bonemeal. The bonemeal is high in phosphorous and promotes healthy root growth. The end result should be a loose, friable soil (like a garden soil that you could easily plant small seeded veggies like carrots or lettuce, for example). There should only be enough soil in the planting hole so that after the tree is planted, there is still a 2 inch depression around the tree so that water will soak into the soil around the tree as opposed to draining away from the trees roots due to a build up of soil around the tree. I always carefully remove 2 or 3 inches of soil from the plants rootball so that some of the plants roots are already surrounded with this fresh soil when the tree is planted. This also enables one to spread out any roots that were circling the rootball (if it was container grown) or prune off any broken roots. It is important to cover the root ball of the planted tree with at least one inch of your soil, otherwise, if the root ball is of a different soil type, and it is higher than the surrounding soil, it can act as a wick and dry out quickly, killing the trees roots. The soil must be kept moist when establishing newly planted trees or shrubs, never soggy wet, or allowed to dry out. The soil around the trees should than be mulched with a 4 to 6 inch layer of organic matter to prevent loss of soil moisture, maintain even soil temperature, keep the soil loose and help prevent the growth of weeds.
Once arborvitae are fully established, all that is generally necessary is a sprinkling of 5-10- 5 fertilizer around each tree in early spring to keep them growing healthy and green. If this does not appear to be doing the job, a soil test may be necessary to find out which macro or micro-nutrients are lacking in the soil.
I do not know if your trees were balled and burlapped, or container grown when they were purchased, but if they were ball and burlapped, they will have naturally lost alot of roots when they were dug up. If the 12 foot high trees did not receive adequate water during the dry spell, along with a reduced amount of roots needed to absorb moisture, (even though it is a year later) the direct result would be browning of the needles caused by dessication. Another possibility of browing needles could be a heavy infestation of spider mites or other insects. It won't hurt to examine the trees carefully for pests. If the trees are located near roads, and salt is used for de-icing the roads, splashing salt water will cause browining of the needles. Pesticides will also kill evergreen needles if the pesticde were used in high concentration and close to the trees. (Just some other possible causes of browning).
The only way to help the trees at this time is to keep the soil moist (providing the ground is not frozen) and if possible, provide shelter from the prevailing winds by placing burlap in front of the trees. Spraying the foliage with water from a garden hose during warm spells will also help reduce further dessication of the needles.
It would do the trees more harm than good to try and transplant them at this time of the year. Early spring is the best time to transplant arborvitae, at least in the colder regions of our continent. If the trees must be moved in the spring, it will be best to try and dig up a larger root ball in order to try and save any new roots the tree has produced over the last two seasons. A further loss of roots at this time when the trees are already stressed will definetly do more harm than good.
