Q: I just walked around my yard and found that my cute little spirea bushes are missing. There are just some short stems sticking out of the ground. I’ve had these in my yard for almost a decade and now, they are mowed off. Do these need to be replaced or is there hope?
A: If this were enough to terminate a spirea, there would be none left on the planet.
These compact, deciduous shrubs, noted for their small, plentiful flowers, are easy to grow in full sun or partial shade. The more sun, the more flowers you get.
Spireas can have bright pink to white flowers. Foliage can be green or yellow. An old-timer called Bridal Veil had arching branches and a profusion of white flowers in mid-spring. Now, there are dozens of varieties (cultivar) with names such as Little Princess, Anthony Waterer, Goldflame and Dakota Goldcharm.
Your most likely shrub-muncher was rabbits. Those little stems are good winter food, but it’s all good. Spireas are one of those shrubs that do better if they are cut to the ground periodically. They bloom best on young wood, so should be trimmed periodically to encourage new, vigorous shoots.
On a three- or four-year rotation, you should prune to the ground as soon as the shrub is done blooming in the spring.
This can be done with other shrubs that produce multiple branches from ground level. Forsythia, lilac, weigela and mock orange will do well with this type of pruning. Cut them down following blooming. Then, thin emerging shoots if there are too many.
If it is a dry season, keep the shrub watered but you should not need to fertilize it.
In the future, you may have to put a cylinder of chicken wire or hardware screening around the shrubs to keep the rabbits out. Do this in November and remove in April.
Q: We burn wood in winter for heat. Needless to say, it makes a big pile of ashes. My husband heard this is great fertilizer and wants to dump it on our vegetable garden and lawn. I don’t think this is going to be good. Can you give me a few reasons to try to talk him out of it?
A: Your instincts are good.
Fertilizer is a broad term. Usually, it refers to the Big Three: nitrogen, phosphorus and potassium, which is also called potash. Wood ashes fits into the last category – it is almost all potassium, and raises the soil pH. If you take wood ashes and mix them with water, you created lye, the corrosive stuff in drain cleaners. It’s also how great-grandma made lye soap that children used to fear.
If you want to use wood ashes, you should get a soil test. A test will show the soil’s pH. Soil pH should be 6.5, which is slightly acidic. If the soil has plenty of potassium, adding more is a bad idea. Much Michigan soil is alkaline, and if there is a big enough overload, the soil could be ruined for years.
For the same reason, you don’t want to toss the wood ashes into a compost pile, either.
Questions? Contact the MSU Extension Master Gardener Hotline at 888-678-3464. Gretchen Voyle, MSU Extension Horticulture Educator, retired.
