GARDENER'S MAILBAG: Why is my sago palm not growing from its central stalk?
Dear Neil: As you can see, my sago palm is growing prodigiously from its base. However, nothing is coming from the central stalk. Is that normal? If not, what should I do?
The old leaves that froze were attached to that stem. You have trimmed them away, and since the stem froze, it is not putting out any new growth itself. All of the sprouts are coming from the root system, So that stem can be removed by cutting it away carefully at any time. Try to do it before much more new growth is produced on the sprouts so that you do not damage to them.
Dear Neil: In having our yard landscaped, we planted four Japanese yew shrubs just a few days before the extreme cold last February. I have attached photos of them so you can see how they look today. I am hesitant to replace them, even though they look pretty rugged. They were expensive, and I would like to save them if we can. What are your thoughts?
Your plants vary a good bit from one photo to the next in how they took the cold. I can imagine how nice they probably looked when you planted them, and I know that’s the appearance you want. Honestly, I would replace them in my own landscape because it’s going to take several years for them to recover. And, they’re not going to recover at the same rate. Have you considered using Oakland hollies? They grow to be somewhat the same shape and size and are considerably more durable.
Dear Neil: As you can see from my photos, our pittosporums took a real hit in February’s cold. They are 26 years old. They’re sending out new growth up and down their stems. I know we will need to prune them to get them to fill back in again, but I am wondering if I need to wait until winter to do it. It seems so harsh to prune them in the middle of the summer.
You can prune dead wood out of them now without harming them in the least. However, I have to admit that I would simply replace them. As with the Japanese yews in the earlier question, these will take so long to fill back in again that I think you’d be better off starting with new, vigorous nursery stock. It probably would save you a lot of heartache and four or five years of waiting.
Dear Neil: I recently planted vincas in a 3-gallon container. I used vincas in the same container last year, but I did not change the soil this time. Now, some of the plants are beginning to die. Should I have used new soil? What might the problem be?
Without a photo and without a description of what the plants look like as they are dying, I’m going to have to make a couple of guesses. Potting soil deteriorates after a few months. The organic matter in the soil mix decays and no longer gives the benefits that your plants need. More than that, however, vincas are subject to a soil borne disease called Phytophthora. It’s a water mold fungus that splashes on the stems during rainstorms and careless irrigation. The stems develop gray lesions that look like someone has placed a hot knife against them. The stem tissues shrivel, and parts of the plant begin to wither. Before long the entire plant is lost. There is no effective product on the market that will stop this disease. The variety Cora XDR vincas have been bred to have disease resistance to this malady, but you still need to practice very good management to avoid it. Wait until June to plant your vincas. Use loose, highly organic potting soils and start fresh each year. Do not allow water to splash onto the plants’ stems and leaves.
Dear Neil: Is the problem with my hollyhocks too much water, or do I have an insect problem?
Neither. Google “hollyhock rust” and you’ll find your answer. It’s a fungus. You’ll also see suggestions of keeping the plants watered well, but keeping the foliage dry in the process. You’ll want to buy healthy, vigorous transplants at the nursery and get them set out early so they’ll have a good chance of missing this common problem.
Dear Neil: I planted this redbud a couple of months ago. This morning I found this damage on it. What should I do?
You have leaf miners. They are small larval insects that work their ways through the leaf tissues as they eat their tunnels. Eventually they pupate and emerge as adult insects to mate and lay eggs, to start the cycle over again. Your best prevention will be a systemic insecticide applied in May each year. By the time you can see this type of damage, there is a little you can do.
Dear Neil: Please advise. I don’t know what to do with my oak tree. I had it pruned late last year so we could get additional sun to our grass. I believe it was pruned incorrectly. The tree service removed all the leaves off the branches and just left leaves at the ends of the limbs. The tree now has suckers all over those branches and the ends are bare. It is a 35-year-old red oak. What should we do?
Leave it alone for now. The one thing you did take into consideration (apparently) was the impact the February cold had on red oaks. Many of them were affected much more than your tree. That’s why you are seeing the tip dieback and the new sprouts along the branches. It should fill back in by next year. Thinning the canopy is usually just a temporary fix, even in normal years. I wouldn’t do that again for a while.
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