This week I answer reader mail:
Q. How can I tame my boulevard? It has five wild cherry stumps that are still budding and are homes for ants and their friends. They are surrounded by thick ivy and blackberry plants. Do you have any suggestions how I can eradicate all this?
A. Blackberry plants and ivy are both resistant to herbicides. That's why your first move should be cutting back your blackberries and ivy with a lopper. This clears the way for stump removal.
After that, you need to decide whether you can cut the stumps down to ground level yourself. If you can't, you should go to a machine rental place and rent a stump grinder. Stump grinding is very hard work and is best done by an experienced operator.
After that, string trimming and regular mowing should keep everything under control.
Q. I have two large hydrangea bushes that look healthy, but in the last two years they have become spindly looking. The blossoms still look great but I feel I'm not pruning them correctly. I'd like them to stay about the same size and look lush. Also I've been told I can affect the colour of the blooms by adding something to the soil. Is it fertilizer or bone meal or something else?
A. I'm assuming your hydrangeas are the mophead type with big, dome flowers. It's best to leave as many dead flower heads as possible on the plant over the winter. These will help protect the buds below from frost.
Spring is the time to prune hydrangeas. Every year it's best to cut the spindliest shoots down to the ground and also one or two of the oldest, scraggliest stems. This will help vigorous new stems to shoot.
The remaining branches that flowered last year can be cut back to fat buds. These will produce flower heads in late summer.
If you ever have to deal with a really ugly, lanky hydrangea, you can always cut the whole lot down to ground level, and provided it's not diseased, it will re-shoot. Hydrangeas are very strong shrubs.
It's acidity that supports the blue in hydrangea flowers and alkalinity that supports pink ones.
Because our soils in B.C. are quite acidic, hydrangeas that are blue when you buy them tend to stay blue as long as you don't fertilize them with something alkaline like lime, bone meal or mushroom manure. If you do, then pink tones will creep into your blue-flowers which morph into a muddy mauve. If you buy a pinkflowered hydrangea and want to turn it blue, you'll need to add something acid-ic like aluminum sulphate.
To get hydrangea colour to persist in earth that's naturally more acidic or more alkaline than the soil it originally grew in, I'm sure you'd need to administer the acidic or alkaline substance several times a year because our heavy rains would tend to leach it through the soil.
News flash: The Alpine Garden Club of B.C. Fall Plant Sale happens from 1 to 4 p.m. on Sunday, Sept. 23 in the VanDusen Garden Floral Hall.
Anne Marrison is happy to answer garden questions. Send them to her via amarrison@shaw.ca.
