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 Aug. 10 show:
Read more:
- Garden Talk: What can I do about mushrooms in my lawn?
- Garden Talk: Tips and tricks for growing vegetables and fruit in Saskatchewan
- Garden Talk: How can I prevent maggots in my cherries?
- Garden Talk: Give your summer lawn some love
These questions and answers have been edited and condensed for clarity.
Q: Can I grow potatoes from seeds harvested out of the pods?
A: You can try to get them to grow, but the best way to grow potatoes is
from tubers because you don’t know what type of potato you’re going to get with seeds because it’s been pollinated. You might not get the same variety as what
you had planted it depends what they’re crossed with.
After harvesting, store the seeds in a cool, dry place or even put them into the fridge, often a fridge is too humid and the seeds will start getting moldy.
You can start planting them in early April or end of March inside.
Q: What causes scabs on the skin of my potatoes?
A: Always rotate your potato crops by planting in a different location every year. Don’t put them in the same place. And potatoes don’t like a lot of compost. No manure or that kind of stuff because it will cause a potato scab.
You can also lower the soil pH, because potato scab doesn’t survive as well in a low pH soil. Lower it to around 5 or 5.2.
Q: What can I do about yellowing on Swedish aspens?
A: Deep root fertilization might help. Get a Ross root feeder and you can put pellets into it and hook it into your hose, then stick the rod into the ground. Do that about three or four feet away from the tree.
If the trees are drowning in water, they’ll turn yellow as well so check the soil. So sometimes it can be too much water. If the yellowing is just in between the veins, then you’ve got an iron deficiency, which usually means a water issue. Use a piece of 3/8th rebar to probe down 8 -12 inches and pull up a sample to see if it’s soaking wet.
If the whole leaf is turning completely yellow then that’s a different issue. Watch for little holes and and sawdust at the base of the tree as well that might mean it is poplar borer.
Q: Can I prune a linden tree now?
A: Now it’s not a problem. They’ve done their major growth now. Don’t prune linden in the spring because it’s pushing too much sap but you could do that either anytime between now and the end of October.
Q: My mandevilla is green and healthy looking, but has no flowers. Why is that?
A: If you’re fertilizing with a 20-20 well-rounded fertilizer, try pumping that middle number up and try a 15-30-15. That might help your plant bloom. It might be getting too much nitrogen which promotes new growth. Fertilize it every two weeks starting at Mother’s Day.
Also add some alfalfa pellets because you’re probably all out of your other
micronutrients which your other fertilizers don’t have, like boron, magnesium, and calcium.
You could prune about a third of it off this year to help promote some new growth — the buds on a mandevilla come from new growth.
Q: Why did many of the blossoms on my beef steak tomatoes fall off?
A: It could have been that they never got pollinated and they won’t produce a fruit if that is the case. It could also be that they got too dry when they were blossoming. To pollinate, be the bee by using a Q-tip.
Q: How do I get my roses to bloom again this year?
A: When you cut the dead head off, go down to the first six leaf branch.
Then you just need rose specific fertilizer to get new growth. They’ll re bloom on new growth. You need to do that throughout the year, starting around May 10 and do it every three weeks. It’s too late to start to do this now, roses are done for the year.
If you have an organic, vegetable fertilizer, which only has like a one or two nitrogen in it, you could give it some of that now to make the plant stronger for the winter. Okay. Don’t use 20-20-20 or 30-10-10, they have way too much nitrogen for this time of the year.
Q: What’s the best chemical for controlling kochia (burning bush)?
A: It’s an annual so if you have to spray it use Roundup, but the best thing to do is to pull out from the root before it sets seed, because it has a zillion seeds. cut off the head. Don’t throw it on the ground because it’ll still go to seed, and even if you spray it, it’ll still go to seed.
Q: Can I plant raspberries or blueberries or similar this fall or do I have to wait until spring?
A: If you want to plant raspberries you need to do that in the spring. You probably could find some Saskatoons and blueberries to plant now in garden centres.
Raspberries have been a hard commodity to find this time of year, but Saskatoons and blueberries can be rooted in right now,. Use an H-start probiotic or a mycorrhiza when you’re planting to get those roots developed a little bit more.
Q: How can I control weeds in a farm shelter belt with Manitoba maple and green ash?
A: The problem with spraying is you’re going to get a lot of drift, that will especially effect the maples. You’ll see the leaves start to curl.
If you want to spray do it in early spring before they leaf out. You could do it in
fall with a hand sprayer and do it when it is dead calm to minimize drift, which can affect the tree growth a bit
Maples are almost an indicator of any kind of herbicide, they’re the first trees
that will show it in the leaves because they’ll start curling up really tight.
Q: Are there any shrubs that can’t be pruned in summer?
A: Don’t prune a hydrangea right now because they’re in beautiful bloom. Prune any flowering plants carefully, but otherwise plants like dogwood and ninebarks can handle a light pruning.
If you want to do a major pruning, or ycut them down to the ground wait until they’re dormant.
If you are pruning in summer, don’t do it on a really hot day and make sure the water gets to the plants.
Q: What is wrong with my bleeding heart plant (pictured above)?
A: It could be two things. It might be nutrient deficient, so give it some 20-20
fertilizer.
Also, sometimes bleeding hearts go through a cycle where they’ll go dormant in the heat of the summer. Try giving it a trim, cutting off about a thirdof the plant and then in fall cut it right down to the ground after it
starts losing its leaves.
Watch the moisture, bleeding hearts don’t like it too wet, but they do not like it dry. Next spring start using 20-20 fertilizer around Mother’s Day, applying it every three weeks.
Q: What is the best way to control thrips on dahlias?
A: Dahlias are really tricky. Using some beneficial insects is probably the best
way. Once we get into the heat of the summer, if you’re growing them in a greenhouse setting or anything like that, the thrips just attack the flowers.
If you want to use them for cut flowers, mix up a bucket of insecticidal soap and dip the flowers.
Thrips are a tough one. They’re so tiny and they’re thin and a lot of the chemicals that you can spray to control them will ruin the flowers.
Q: Can I use dormant oil to control rust fungus on Saskatoons?
A: Dormant oil is a good way of suppressing it especially in the fall or the spring
but only when the leaves are off the plant. Also you can use copper sulfate.
Q: Why do my hollyhocks have yellowing leaves and are not fully blooming?
A: It sounds like it’s a nutrient deficiency, so make sure you’re fertilizing them like every two weeks with a 20-20 or 15-30-15 fertilizer,
Hollyhocks will sometimes reseed themselves, so if you don’t want them to reseed in random spots just you’ll have to deadhead.
When hollyhocks are younger a light pinching pruning will help with some bushing and branching and might get new growth, which will develop more flowers.
Q: I have a lot of Corentine cucumbers, but what’s causing some of small one to turn yellow?
A: It might just be that the plant has too many cucumbers on it to be able to take all of them to their full potential.
Thining out your cucumbers is a good idea or when they get to the blooming stage, thining those out might also help.
Q: How can I stop my corn laying flat on the ground?
A: Stake it up if it’s a little hard time standing up on its own. Get some bamboo stakes and string.
Q: What can I do about a branch on an oak tree that is sagging because of the weight of the of the acorns?
A: Cut the acorns off. If the tree is making a lot of acorns, it means it’s stressed out and is trying to reproduce itself.
Watering and fertilizing the tree might help, but it takes a lot to stress an oak because it sends a taproot down to the water table.
Q: Is there any way to control chickweed?
A: Make sure it doesn’t go to seed. Corn gluten can be used if it is in the grass but you can’t use corn gluten in the garden. Pick it so it doesn’t go to seed.
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