Each week, Susan Richards of New North Greenhouses answers your gardening questions. Have questions about your gardening needs? Please email her at firstname.lastname@example.org
Strina: I just noticed mottled colouring, a very pale yellowish, on the leaves on my 3 Annabelle hydrangeas. My neighbour has the same mottled look on hers as well and black on the edges on some of the leaves. My plants face south so they get plenty of sunshine but hers faces west. I fertilize mine and the blooms have always been huge. I hope I’m not going to lose these shrubs . . . they’re 11 years old.
It sounds like it you may be dealing with a disease called rust. Look under the leaf to be sure. You will see rust coloured tissue if this is the problem. The fungicide sulphur helps to control rust. Spray the top and underside of the leaves to prevent the disease from spreading.
Also, make a point of changing your watering practices especially during period of hot humid weather. Soak plants at the base and keep foliage dry.
Tracey: My peony has finished flowering and seeds are forming. Do I leave those seeds to develop?
Peony are propagated by dividing, not from seed, so prune off flower stocks as soon as the petals drop. There is no use allowing the plant to waste energy on seed production.
Flowers you want to spread by seed should be left alone until seeds mature. Then you can collect them or let the seeds fall naturally to self-propagate or 'volunteer'.
Steven: I have holes in the leaves of my lilies and see a red beetle. Is this doing the damage? Is there an insecticide I can spray on the foliage to prevent them from eating the leaves?
Yes, that is the Red Lily Beetle and no there is no preventative spray on the market in Ontario. I've found picking the beetles and drowning them in a container with a rubbing alcohol/soap solution the best method for control. The ratio of ingredients isn't important, just be sure to have more alcohol than soap or water so beetles perish immediately.
Lily beetles quickly drop to hide in the soil when disturbed, so hold the container of solution right under where you see the beetle. When you reach to pick the insect, it will drop straight down into the container.
Also be on the lookout for the larvae of the beetle. It will look like a clump of black goo the underside of the leaf. It actually coats itself in its own excrement to hide from predators!
Pick off infested leaves or if you're not squeamish, squish the larvae between two leaves.
Karen: I have small shoots forming in the 'V' between the main stem and leaves of my tomato plant. Do I remove those?
Yes, you should pinch those off. Your tomato plant will get too thick and bushy if you allow all those shoots to develop. You want existing branches using all its energy to produce fruit rather than sucker growth.