The third week of September is a good time to add asters, chrysanthemums and winter pansies to the landscape. If your sedum ‘Autumn Joy’ plants are falling forward with their heavy blooms surround them with stakes and corral the floppy stems with twine. Best to do this job on a rainy day or you’ll be fighting off the bees.
We grew some great raspberries this summer and even had a crop late into the summer. I do not know what type of raspberries we have because the starts were given to us by a friend. When does one prune raspberries? – S.W., Puyallup
Grab your clippers now and get to work. This is the time to cut all of this year’s raspberry canes right down to ground level. These will be the canes turning yellow that already bore fruit. Do not prune the green canes that sprouted this summer. Tie these new canes to a horizontal support so the berries will be easy to harvest and the raspberry plant easier to control. Pamper your raspberries with a manure mulch in early spring and you’ll be jamming all next summer.
I have a mock orange shrub that did not bloom. The leaves are green and look healthy and this shrub has been in the ground for several years. My neighbor has the same problem. What is going on? – D.M., Buckley
Apparently not much is going on with the sex life of your mock orange. These old-fashioned shrubs bloom with fragrant flowers only when they are mature enough to handle seed production – and that can take many years.
There is a mock orange native to Western Washington that seems to bloom more reliably. It goes by the name Philadelphus lewisii – named after the Lewis and Clark explorers. Don’t prune a mock orange or any spring blooming shrub in the fall. Pruning after blooming is the general rule of green thumb.
You could try adding a slow release plant food such as Osmocote around the base of your mock orange plant and waiting a few more years to see if it will stop with the mocking and start with the blooming. Or give it one more year to mature then resort to the shovel solution and dig it out. Life is too short to put up with ugly or ungrateful plants.
My hydrangeas were beautiful this summer. How do I dry the blooms? When can I cut them and prune my hydrangea? This shrub is almost as tall as my house! – O.L., Tacoma
Congratulations on your mop heads. Early autumn is the perfect time to cut big leaf hydrangea blooms for drying. Cut the stem and remove all foliage. Stand each stem into a bottle or shot glass with just one inch of water. As the water evaporates the hydrangea flower will dry naturally. Keep the dried blooms away from sunlight or they will fade.
To prune hydrangeas cut out the old, dead wood and shorten the longest branches in early spring or fall. Most big leaf hydrangeas flower on two-year-old wood so if you cut back all of the branches by more than one-third you will be cutting off next year’s flowers. The happiest hydrangeas are those left unpruned. Big leaf hydrangeas want to be left alone so they can grow into the dominate divas of the garden that they were meant to be. If your hydrangea is growing too large for her space, consider moving her to a bigger stage where she can belt out the blooms without restrictions as a reward for her awesome performance. Hydrangeas bloom better here in Western Washington than anyplace else on Earth. Enjoy.
Marianne Binetti is author of “Easy Answers for Great Gardens” and eight other gardening books. She has a degree in horticulture from WSU and will answer questions at binettigarden.com.