Garden Talk: What are those white fuzzy spots on my plant?

Jill and Rick Van Duyvendyk answer all your gardening questions in Garden Talk on 650 CKOM and 980 CJME every Sunday morning at 9 a.m. Here are some questions and answers from the June 8 show:

Read more:

• Garden Talk: How can I stop voles invading a garden bed?
• Garden Talk: Tips for planning a thriving home vegetable garden
• Garden Talk: Save money by being water wise in your yard this summer
• Garden Talk: Can fruit be affected by wildfire smoke?

These questions and answers have been edited and condensed for clarity.

Q: What causes white fuzzy spots on my plant?

A: It’s mealybugs, and they do look like white cotton. If you look closely at the bug, it has two little antlers on it and scoots around. It’s got different stages — a crawling stage, and a fuzzy egg stage.

Best thing to do to get rid of them is Safer’s End-All. It is a soap product with potassium salts of fatty acids derived from natural fats and plant oils.

Another thing that works well is using a Q-tip with some rubbing alcohol or diluting some rubbing alcohol 50 per cent and spraying that on the plant. That will kind of melt away the mealybugs, but you have to stay on top of it. Do it every 10 days for about four applications.

Q: Can I plant potatoes from the grocery store?

A: Yes. They’re not certified as seed potatoes and they need to have an eye on them that’s starting to sprout. Sometimes they are sprayed with a product to not let them sprout.

Q: Can I still trim our cherry trees this time of year?

A: You can do some light trimming because cherry trees are in full leaf, have finished blossoming and are starting to set fruit already. You can do a little bit of trimming, but not a major trimming — don’t cut them in half or anything.

Q: What causes small holes in hollyhock leaves?

A: It could be fungal. Sometimes if water droplets sit on the leaves it will start a fungus on the leaf and the green part just falls out of the centre and leaves a hole.

It could be a worm eating them, and we’re seeing lots of worms right now. Look for bugs on the underside of the leaf and on new growth, and also look at night.

Q: How do I prevent radishes from bolting?

A: Bolting is usually from heat, so put a shade sail over them when they get more mature. Also make sure that you have a light, fluffy soil. If the soil is too hard, it will cause your radishes to bolt as well.

Also too much in the way of nutrients can cause it. Ground crops don’t like a huge amount of manure — for potatoes, carrots, radishes, and onions, don’t put a ton of nutrients in the soil.

Only furrow a little row for radishes, and use 25 per cent of your seed into the ground. Then the next week another 25 per cent, etc.. Then you’ll have nice fresh radishes throughout the different parts of the summer. Radishes are a cool weather crop so it is best to grow them early in the season and then in the fall.

Q: I planted two ninebarks about five years and one is about five or six feet, and the other one is about one foot and never grows. Why is that?

A: It could be a number of things. It could have been that plant was root bound in the pot which makes the roots choke themselves off.

It could be the soil heating up differently in the spring so one gets more winter kill because of the way that the snow falls or it could be a simple thing like one’s closer to the sidewalk and you shovel off the walkway which you put salt on in the winter.

Q: My irises have finished blooming. Can I divide and split them now?

A: The best time to divide and split them is when they’re dormant in early spring or late fall.

Q: How long do Ihave to wait to replant rhubarb in the same area after it had red leaf disease?

A: Three years.

Q: My 50-year-old pyramid cedars had lots of winter kill this spring mostly on
the bottom. Do cedars only live so long?

A: Apart from watering and fertilizing, the only thing you need to watch for once they get that old is that they get really thick and then they don’t get very much sunlight on the bottom. It’s going to be really hard to get it to fill back in, so put some annual flowers around the base like impatiens or fibrous begonias because it is shady there.

Fifty is old for a plant, so if they don’t come back in a year or two and they stay sparse at the bottom, it might be time to consider replacing them.

Q: Is there, there is a Reliance peach I can plant in zone four?

A: No, we’re too cold. You’d have to bring it indoors for the wintertime and treat it like a citrus.

This is the gardener’s challenge here — to get it to live in a pot, move it outside for the summer, bring it back in for the winter, let it go dormant with a bit of frost on it, but just so that the roots don’t freeze solid. Then you bring it inside, let it go through a dormancy period, and get it growing again in January or February.

Q: The tomatoes I planted on May 11 are not growing, why is that?

A: It’s because we got a cold snap right after you planted them so they are set back a bit. They will take a little bit more time getting going again.

Fertilize them about once a week, but as soon as the heat comes, you’re going to see them put on a lot of growth.

Watch you’re not overwatering them on cooler days. Next year, wait a little bit longer, until the May long weekend, before you get them in the ground.

Q: I want to move my hydrangea over a few feet, is it too late?

A: Yes, it’s pretty late. The only way you can move it is if it has been planted fairly recently. Take a shovel and a good ball of soil with it, but if it’s been in the ground for a couple years, wait until next spring.

A: My big evergreens have needles dying on the bottom and constantly they’re losing needles. What causes that?

A: It could be spider mites. You’ll never get them all but you can control them and spray the bottom half of the tree. Use Malathion.

If you the browning is happening sparsely all through the tree, then you might have
needle cast and then you need to spray as much as you can. There are attachments now that you can put on to your end of a leaf blower so that you get it up taller.

Or you can put the spray into a barrel with a submersible pump and hook it to your pressure sprayer to shoot it up. Wear a mask and close your windows. Spaying by helicopter or plane also works.

Q: Can you plant a lilac tree beside a flowering crab tree?

A: Yes, just remember some lilacs grow small and some of them grow 12 feet.

Q: I planted sweet pepper seeds that came from peppers from a grocery store, but they won’t germinate. Why is that?

A: Some of the varieties are hybrids, so their seeds aren’t going to be viable. With peppers you want to be starting then indoors in in March and in February for some hot peppers, so it might just be a little too late.

It is best to get your seeds from a viable source — you want to be successful if you’re putting all the time and energy into them.

Q: How long can I plant garlic in the same place?

A: Garlic can generally be planted in the same place for quite a while. It doesn’t use a lot of nutrients in the soil.  With ground roots it is best to rotate your crops in case there’s any kind of fungals in the soil.

Q: How do I improve my garden soil which has a pH of seven?

A: Add gypsum or sharp sand, which is little stones that have been crushed. Don’t use sand box sand or beach sand.

Q: I planted asparagus three years ago, last year we had a few little ones but this year there’s nothing. What’s going on?

A: It might just be taking time for the roots to grow. It usually takes about three years for it to get full size. Leave those fronds, don’t cut them back until they start becoming about the size of a pencil or your pinky finger. Once that width is there, then it’s time to harvest. Otherwise, leave the crop alone.

Read more:

• Garden Talk: How can I stop voles invading a garden bed?
• Garden Talk: Tips for planning a thriving home vegetable garden
• Garden Talk: Save money by being water wise in your yard this summer
• Garden Talk: Can fruit be affected by wildfire smoke?