This week I answer questions from readers: Q. In 2010 we planted a row of raspberry plants in good soil along the south wall of the house. We put manure on each spring and we have a sprinkler system (except not right now), but we don't have raspberries. There aren't many blossoms and although there are bees around, there are only a few, and mostly very small, berries. When we had other raspberries elsewhere we had no problem. I'd appreciate any advice.
A. A garden bed under a south wall is usually the sunniest and hottest place in a garden. The foot of a south wall is also the driest spot, not just because of sun but also because foundation drains are usually placed deeper down along the house wall.
If you have a roof overhang there, it will be even harder to moisten your south-wall soil to the degree raspberries like. They don't need to be in a swamp, but they do need soil that holds moisture.
As it is, the hot sun and high temperatures this year would have sucked away the sprinkler moisture even while it's being applied - that is if you have an above-ground sprinkler.
Some gardeners call underground watering setups sprinkler systems, but if yours is underground, the result wouldn't be much different due to hot sun and underground drains.
You would have more productive raspberries if you moved them to another site away from the south wall. If it's in semi-shade, that's no problem for raspberries.
Adding some Sea Soil or manure to earth in the new site would help retain moisture. So would mulching the raspberry plants. You could use grass clippings or bark mulch. Peat isn't a good choice for mulching. Aside from environmental concerns, peat is so hard to moisten once it gets dry.
A letter from Keith in Burnaby has underscored the importance of checking the best-before date for nematodes.
Last week, he picked up a package of nematodes from a very reputable hardware store - one of a chain across Canada.
Keith writes: "When I got home, I noticed the best before date was May 31, 2015. I called them to see if these nematodes would still be OK to use. The reply was that they should be OK, but I could return them if I wanted.
"I was advised by the company that produced the nematode product that the nematodes were probably dead and should be returned to the store I purchased them from, which I did."
Keith then went to a big box store and bought another package of nematodes. "Our package best before date was Sept 15, 2015. If they don't sell quickly, how long do they keep these nematode packages in a fridge? More than two weeks?" The chafer-fighting nematode (Heterorhabditis bacteriophora) can be used effectively only for about two weeks in late July, which is usually when chafer eggs hatch.
But the issue isn't only how long nematodes stay alive prior to use.
If the nematodes are used later than the end of July, the chafer larvae have grown large enough to delve deeper into the soil where the tiny nematodes can't catch them.
Anne Marrison is happy to answer garden questions. Send them to her via [email protected]. It helps if you give me the name of your city or region.
