1 - Desiccation of newly planted landscape plants may be caused by many factors.

Yard and Garden May 6, 2017

Q.

I just moved into a new home in Metro Verde that backs up to BLM land. I bought 2 dwarf arborvitae plants and a blue point juniper which I kept in their original pots for about 1.5 months. I planted the dwarfs and one seems OK, the other is drying out horribly. Due to the next door neighbor flooding his yard I could not plant the juniper yet, as my yard was catching a lot of his water and it would have killed the tree.

I just noticed the juniper is also crumbling apart and I have faithfully watered all of them this whole time. I have watered every other day. I do not know why the one dwarf and the juniper are in such shape and if there is any hope for them nor how to save them. If you just barely touch them, the needles crumble right off

Then there is a small spineless cactus I planted in special cactus soil and it started getting light brown at the base, eventually all the pads began shriveling up into nothing. I do not understand what I am doing wrong! I have included photos, if this helps. Any and all advice you can provide would be a God send and I appreciate your time and help in advance!

- Las Cruces
Via internet

A.

This is a challenging question, even with the excellent pictures. However, there are several things to consider that may explain the problem.

First is the possibility that they are getting too much water. I assume the original pots had holes for drainage, but watering every other day may have kept them too moist. This would be especially true in the early spring when temperatures are cooler and the soil does not dry as fast. That may explain the cactus and the juniper, but I am not confident it explains the problem with the arborvitae plants.

The opposite situation should also be considered. Injury may have occurred in the pot when the pots were allowed to dry before the arborvitae shrubs were planted. If one had dried more than the other, or if it was in more sunlight than the healthier one, it would have been more injured. That could explain why one arborvitae plant looks better than the other. Plants in containers can dry much more quickly than plants in the soil. Injury that occurred before planting could explain the symptoms being exhibited now. The juniper and cactus are still in pots and as the temperatures rise, chances for desiccation increase.

Another question is whether or not your home has a water softening system. Water softeners that replace calcium and magnesium minerals in the water with sodium can cause exactly the symptoms your plants exhibit. However, one arborvitae plant is exhibiting symptoms and the other is not as affected. The healthier of the two is closer to the wall in your picture. Is that the wall between you and the neighbor who waters excessively? It may be that his water is not softened and protects the plant nearest the wall from the sodium toxicity. Even that plant is showing some symptoms however, so that may not be the case.

Another possibility is fertilizer burn which could cause these symptoms if the plants were over-fertilized. You did not mention application of fertilizer. Insect sprays could also cause the desiccation of the needles also.

Many different things can cause the symptoms exhibited by your plants, so these are some things to consider. Do any of these scenarios seem possible? If the cause can be determined, it may be possible to salvage the juniper, cactus, and one of the arborvitae plants, but the cause should be determined as soon as possible. Your local NMSU Cooperative Extension Service agent can help you make this determination.

Marisa Y. Thompson, PhD, is the Extension Horticulture Specialist, in the Department of Extension Plant Sciences at the New Mexico State University Los Lunas Agricultural Science Center, email: desertblooms@nmsu.edu, office: 505-865-7340, ext. 113.

Links:

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