Insects and diseases can destroy a garden, but usually they are just annoying. Knowing what to expect and dealing with the problem quickly can minimize damage.
A few spittlebugs in the garden are a common site in June.
The insects overwinter on dead leaves of old plants and hatch about the time the plant begins to flower.
Most often the first sign of the insect is a frothy liquid surrounding a stem that looks like someone spat on it.
The wet bubble material protects the insects as they suck nutrients from the stems. Large stems might become misshapen and thinner ones will collapse.
Spittlebugs can be controlled by either hand picking, squishing or by blasting the foam with a strong spray. When left alone, they do minimal damage.
Black knot fungus is much more serious as it is spreading rapidly, destroying a large number of shade and specimen trees throughout Alberta.
Host plants are trees and shrubs in that bear stone fruit in the prunus family, including mayday, plums, cherries, apricots and flowering almonds.
At first, infected areas swell and turn an olive green. It takes the growth two or three years to mature to the rough black mass that is easier to detect. Once it reaches this stage, it will crack and spores will fall out, infecting other plants.
The only cure is to remove all diseased wood. Alberta Agriculture recommends that all infected branches be removed six to eight inches (15 to 20 cm) below the knot. Always cut back to another branch or main trunk. Leaving stumps is unsightly and those stumps are entry places for diseases, viruses and rot.
In the case of an infection in the main trunk, cut out all diseased wood, going at least a half-inch (one cm) beyond the diseased wood.
All diseased wood must be disposed of immediately. It can be burned, double bagged and sent to the landfill or buried. Materials that are left can and will give off more spores, infecting more plants. For more information go to: http://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/faq7622?opendocument
Ever turn over a tomato and see the centre of the fruit sunken and black? With squash, the fruit starts to grow but rots from the blossom back towards the stem.
Both of these problems are called blossom end rot and are the result of the fruit being short of calcium.
Fruit that starts to rot needs to be discarded but this doesn’t mean that all fruit will be affected. Care needs to be taken to make sure that the plant has enough moisture to absorb calcium and transfer it throughout the plant.
The stronger and larger the plants roots, the more calcium can and will absorb from the soil.
To encourage roots to reach out into surrounding soil, water away from the base of the plant, encouraging the roots to grow outwards.
Allowing the soil to dry between watering when the plants are just set out will also encourage more root growth.
After the first few weeks, keep the soil uniformly moist, making it easier for the plants to absorb calcium and transfer it to the developing fruit.
A common mistake it to over fertilize the plants. If in doubt about the nutrient level, have the soil tested.
When fertilizing, apply as liquid and follow the instructions on the package. Do not over fertilize as high levels of nitrogen can interfere with the uptake of calcium.
There has been some success with squash by hand-picking dead blossoms before they can rot.
A few changes in how plants are watered and fertilized can make a big difference in the fruits produced.
Linda Tomlinson is a horticulturalist who lives near Rocky Mountain House. She can be reached at your_garden@hotmail.com