Q: I am sending along some pictures to see if you can help. The arborvitae has been there for approximately four years and now looks half dead! There is a little bit of green growth on the dead side that you will see in the pictures. Is there any solution?
A: What a beautiful tree! No wonder you're worried. The problem could be environmental. Is the tree getting too much shade on that side? Nearby neighboring trees could have grown and produced more shade as the years have past. Were there any changes to fertilizing, weed control, bug control in the area of the tree? Is there anything else that might have been used on a nearby lawn or garden? Arborvitaes have a very shallow root structure and react quickly to these changes. Maybe a new lawn service used a different product?
Is there a sprinkler system in the area? Arborvitaes cannot stand being drenched with water daily; a deep ground level watering once or twice a week is generally sufficient.
You didn't mention any bugs. I'm sure you looked, but two of the most common and devastating bugs for arborvitaes are red spider mites and spruce mites — and they're too small to be seen without a magnifying lens. Please call an arborist to get professional advice!
Q: I tried planting lettuce a million years ago but my garden is too sunny. It bakes! So I just got three lettuce plants compliments of my sister-in-law and thought I'd plant them in a big container. What do you think?
A: Lettuce is a cool weather crop: keep lettuce in filtered light or morning sun during the summer. You could put the pot on wheels, or you could put a shade over the pot. Remember to give the plants plenty of water and watch out for bunnies and bugs. Then get some seed and plan to start a lettuce crop in cooler weather in the early fall, or early next spring, when you won't have to worry about hot sun.
Q: I bought two dwarf burning bushes from a catalog. They're only about 10 inches tall so I planted them in pots. All is well. Now I am told that they are being banned in Massachusetts and illegal to buy and plant here. Can you tell me what the problem is with these bushes?
A: You are right. State law prohibits the selling and propagating of invasive plants and, as of the past year, burning bush has joined the list! A plant is put on the list because it spreads rapidly and the plant grows so easily in the wild that it crowds out native species.
But if you already own the plants and have them growing on your property, you certainly don't have to destroy them, just be careful where you plant them.
Once a plant is put on the list, it is seldom removed, so cherish your burning bush plants They're quite beautiful!
Q: I have had to pull my hedge up due to the excessive use of road salt on the driveway next to my hedge. This past winter was heavier then usual. I would like to replace them with Rosa bushes if they will withstand the salt. The privet hedge was here when my husband and I bought this house in 1963. Thank you for any advice you can send me.
A: I need some more information: Is the area sunny or shady? I assume sunny if a private hedge grew well in prior years. Has the ground been permeated with salt for many years? If so, you might want to dig out and replace the soil. Sometimes the soil can be flushed with water to lower the salt content if the salt was only occasional.
Don't confuse a plant that will tolerate sea spray, like the Rosa rugosa, with something that you think might grow in salt-saturated soil. They are not the same. The Rosa rugosa is a common beach rose, which requires full sun, will tolerate some salt spray from the ocean and sandy soil. But no plant will tolerate yearly soaking with chemical road salts.
Have you done a soil test recently? A ground cover will be no more tolerant of the salting soil than the hedge, so correct the soil before you waste money on new plantings.
Q: For years I have grown many plants from avocado seeds. One plant stands six feet tall in our living room. For the last few years I have unsuccessfully tried to grow plants from seeds. Nothing happens whether I strip off the skin or not. Do you know why nothing happens?
A: Don't you love avocado plants? I don't want to scare you, but I have one growing in my greenhouse, which has got to be more than 12 feet high. I had to chop off about two feet this year, because it had grown into the venting system in the roof! It didn't happen overnight. I have to admit that the tree is about 20 years old.
I get more and more comments about the seeds not being as easy to sprout as they once were and I really can't explain it! Maybe the avocados we're buying in the stores are being picked at an earlier stage, in order to remain firm and hard for safe, unblemished shipment. The best fruits sprout when they're very ripe, almost rotting.
Maybe they're sprayed with some chemical to retard spoiling which makes them difficult or impossible to germinate.
One suggestion I just read: Seal an unwashed seed in a plastic zip-lock bag with piece of moist paper towel and put it under the sink or in a closet, where it's dark and warm. Check every week or two and add a small bit of water, if needed, and you might also want to change the moldy, rotten paper towel as well.
This person said this never fails to sprout the seed in a month or two. So keep eating avocados and keep trying!
This week's dirt
When you overwater that 6-foot potted tree on the porch or rain fills the saucer beneath the huge potted plant on the deck and you need to empty the saucer, but you can't even budge the plant, think Thanksgiving! Get out the turkey baster! It removes excess water in seconds with no strained back.
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North Shore Gardener by Barbara Barger of Beverly is a regular feature of Wednesday's Lifestyles section. Reach Barbara by e-mail at nsgardener@comcast.net or write to her c/o Salem News, 32 Dunham Road, Beverly, MA 01915. Previous North Shore Gardener columns can be found at www.ns gardener.com.
