Garden Talk: What is the best way to deal with ant hills in my yard?

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 May 4 show:

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

Q: What is the best way to deal with ant hills in my yard?

A: Use nematodes for ants. Wet your lawn deeply because the colonies are almost 12 inches deep, then spray the nematodes down because they can’t go through dry soil. If you just spray the top it’s not going to do anything.

The nematodes will start eating the eggs and the queen will move away, workers will take some eggs with them with the nematodes and eventually it’ll just wipe out the whole colony.

The nematodes are in a powder form that you put into a special sprayer, not a regular sprayer. It will take about seven to 14 days to start getting rid of them.

Read more:

• Garden Talk: When can I transplant a rhubarb plant?
• Garden Talk: Can I grow apricots in Saskatchewan?
• Garden Talk: Tips for planning a thriving home vegetable garden
• Garden Talk: Everything you need to know about caring for your spring lawn

Q: How big should a pot be for a tomato plant?

A: Go at least 16 inches in diameter and about 18 to 24 inches deep, you want quite a large soil volume.

One key to success when you’re putting tomatoes into a pot is make sure you choose a determinate variety tomato.

There are two types of tomatoes — determinate and indeterminate. Determinates are better for pots because you don’t have to stake them and they’re not going to grow really tall.

Water them consistently  — you don’t want to go wet-dry, wet-dry, wet-dry or you’ll get things like blossom end rot.

See Dutch Growers guide to choosing and pruning tomatoes here.

Q: When I should put a praying mantis egg sack outside?

A: Wait until nighttime temperatures are consistently about 10 C. You can also put them inside in a sealed container on a window sill and let them hatch in the house and move them outside afterwards.

There should be some leaves on the plants when you out them out and spray the plants down with water first. The third week of May, first week of June is a good time.

Q: What causes birch tree leaves to curl?

A: Probably a birch borer and it’s really tough to treat. The holes are about the size of a ballpoint pen tip and at this time of the year, they’ll probably have sap dripping out of them.

The only thing you really can do is use Doktor Doom. It’s a pyrethrum spray and comes with a little straw like on a WD-40 can and you spray it into the bore holes.

If there are branches that have turned brown and dead, that branch is not coming back. The borer only go after stressed trees, so keeping your tree watered and fertilized and healthy.

Q: When can plant asparagus outside?

A: Any time now as long as you acclimatize them first. Don’t plant straight outside from your greenhouse. Watch the temperature, but if they get three or four days outside before it gets cool temperatures, they will be fine.

Q: My tomato seedlings have outgrown their three-inch pots, but it’s too cold to plant. What should I do?

A: Don’t worry if they’re a little bit long and lanky. You can trench them — bury them up to their top set of leaves or lay them sideways and have the top come up. They’ll be healthier and stronger because they’re going to get roots all the way up the stem.

Q: Can I remove a branch off my lilac tree now?

A: Yes, but do it right away. If you cut too much, you will cut the blooms off.

Q: When can I plant potatoes and onion sets, and carrot, beet and
lettuce seeds?

A: The ground temperature needs to be about 7 C before you put  potatoes into the ground, any cooler and you might get some rot.

Usually soil temperature will be about that temperature around the May long weekend or slightly before, but if you have a soil thermometer you can go ahead when the temperature is right. Usually if you see shrubs starting to bud the soil temperature is good.

Q: Some of my seed potatoes have developed long sprouts, can I still use them?

A: Cut those sprouts off and you can even cut the potato so there us at least one eye per piece.

Q: When can I divide irises?

A: Right now is the perfect time. Usually want to do it when they’re dormant. Replant them the same depth that they are now and not any deeper. The crown has to be just above ground.

Q: Will Malathion kill ticks in your yard?

A: Yes, but mask up and put gloves and boots on when you spray it.

Q: When can I move a miniature lilac bush?

A: Move it with as much dirt as you can and move it soon. If it’s got leaves on it, don’t move it.

Q: When can I move hostas?

A: Any time now. Try and take a good root ball with them when you’re moving them and if you want to separate them, the sooner the better.

Q: When can I plant a hydrangea? And what type do you recommend?

A: Anytime now but get a hardy variety. The type depends on the size that you’re wanting and the shape of the blossom. Think about your area and how big, how wide and how tall you want them.

Q: Can I start rooting hybrid poplar cuttings now?

A: You should have taken cuttings in March or at the beginning of April before they bud out, but if you’re gonna take them take them now put them in a pail of water and get them to root and then plant them or you can put them straight in the ground.

Q: How can I successfully move peonies?

A: Do them right away. Take a good root ball and do it when the plant’s dormant is the best time.

Q: Is it too late to prune a grape vine?

A: No, but do it right away.

Q: Can I trim a branch that’s partially broken off a maple tree right now?

A: If it was broken you can cut it now.

Read more:

• Garden Talk: When can I transplant a rhubarb plant?
• Garden Talk: Can I grow apricots in Saskatchewan?
• Garden Talk: Tips for planning a thriving home vegetable garden
• Garden Talk: Everything you need to know about caring for your spring lawn