Browning of Alberta Spruce can be caused by a few things
I planted an Alberta Spruce (almost 3 feet tall) into a ceramic pot measuring approximately 2 1/2 feet high and twice the diameter of the plant’s root ball. It is planted in good soil and the pot has holes for drainage.
Toward the end of summer, the needles turned brown beginning at the top of the plant. Since then, the entire plant has needles turning brown and falling off.
The plant is located primarily in a shaded area of our patio, facing east and close to the house. Can you offer advice so it won’t die? I’m particularly concerned now that it is winter.
When the needles of a Dwarf Alberta Spruce start browning and falling off, it’s usually because of one of three possibilities: water, sun or spider mites.
Watering issues are the most common problem I run into. Most spruce are not drought tolerant plants, so providing a regular supply of water to the soil is essential. They don’t want to live in a swamp that’s constantly wet, but they can’t dry out too much.
Actually, I’ve seen quite a bit of drought damage this year because of the warm and extremely dry spring and early summer. It is possible your plant just went a little too dry earlier this summer and you’re now seeing the effects.
If this is the case, there is really nothing for you to do about it now. The damage has been done. Concentrate on regular watering, and give the plant time to recover and grow out new growth to cover up and replace any dead.
While I’m on the topic of watering, it’s extremely important to water your plant over the winter. Surprisingly, drought can harm plants just as much in the winter as in the summer. You won’t have to water as often when things are cold, but I’d figure on giving the plant a gallon or two once every three or four weeks. If the weather’s warmer, it may even be more often than that.
The second possibility, sun, probably isn’t an issue for you. In spite of what the tag on the plant might say, Dwarf Alberta Spruce much prefer a shadier spot around here.
While they might tolerate full sun in Portland or Seattle, our thin air, bright sun and low humidity force us to give them a bit of shade in the afternoon. The spot you described sounds pretty good to me.
The last possibility, spider mites, usually crops up early in the spring. Spider mites damage plants by sucking the sap from the foliage, resulting in a brownish, bronzy look and damage or die-back to the plant. Mites are really small — barely visible to the naked eye — but they make up for their size with numbers. There can be thousands and thousands of these guys present, and it’s those numbers that get to the plant.
While most mites prefer hot and dry conditions, this particular species of mite, the spruce mite, likes it cold and dry. Most of their damage is done late in the winter, but people usually don’t notice it until April or even May.
This doesn’t sound like what’s happening with your plant, but I thought I’d mention it. But if you’re worried about mites, clip off a little branch or two, put them into a Ziploc bag and take it to the CSU Extension or bring it out for me to look at.
If we find mites, they are easy to spray for and you already have the best spray at home: water. Just take the hose and give the plant a good hard shower with cold water.