The month of April is a warning to April fools. Spring may be sprung, but summer still is months away and this is not the month to introduce frost-sensitive plants to the garden no matter how mild our winter weather.
Do not plant geraniums, petunias, tomatoes, cucumbers or other warmth-loving plants until after all danger of frost has passed — usually sometime in mid-May.
April is a good month for planting trees, shrubs, roses and perennial plants, such as hostas, and rock garden plants. Hardy sedums and succulents, and cool-season vegetables are ready to go now, too.
A few questions from readers:
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Q: I have clematis that flowers in the summer — I think it is called Mr. President. It had been growing on a trellis, but the wood has rotted and I want to replace the old trellis with one made from metal. My question: Can I cut the long clematis stems to the ground for a fresh start? I do not want to kill this clematis as the flowers are lovely. — P.P., Puyallup
A: I vote to give Mr. President the ponytail cut now for a fresh start on the new support system. The pony tail cut is when you grab all the stems in one hand about a foot from the soil level and snip like you would if you were cutting off a ponytail. If you prune a summer flowering clematis in early spring, it will still elect to give you blooms that same summer — just expect the flowers to show up later in the season. Most overgrown clematis vines can be pruned back to 12 to 18 inches from the ground if necessary to clean them up or start fresh growth.
Q: I decided to patch some bare spots in my lawn last month and so I spread a sandy, two-way mix of soil in the empty spots, sprinkled grass seed then covered the seed with compost that I purchased in a bag from the garden center. It has been four weeks and no sign of new grass sprouting. What do you think happened? — C.C., Renton
A: The clue to this mystery of the disappearing grass seed is that you covered the seed with compost. Grass seed will not sprout in cool weather if it is hidden under a blanket of damp compost. Just barely cover the seed with a very thin layer of peat moss or a tiny bit of compost by raking the topdressing lightly over the seed. In Western Washington our damp spring weather means grass seed will sprout sooner if left uncovered – if you can keep the birds from removing the seed. When it comes to reseeding bare spots, you can now find “lawn patch repair” seed mixes that are sold with bits of tissue paper and mulch mixed right into the seed. This is a good way to seed the lawn without burying the lawn seed too deep while still protecting it from the birds.
Q: I bought a dwarf mugo pine a few years ago and it is now four feet tall and four feet wide. My neighbor has a dwarf burning bush with the name ‘compacta’ at the end that has also grown into a huge shrub five feet tall. We have very small yards and want to know if there are any shrubs that will stay dwarf or compact. We no longer trust the plant tags that say a shrub is dwarf. — M., Email
A: Just ask for “true dwarfs” at local nurseries. Specifically ask for shrubs that will grow just 1 inch toa 1/2 inch a year. The cone-shaped dwarf Alberta spruce comes in both a semi-dwarf form (the most common) and a true dwarf that will stay under two feet tall after 10 years. There also are evergreens with round bun forms, weeping forms and lovely upright, but very narrow forms that serve as “exclamation points” in the landscape. These true dwarfs are often sold as rock garden conifers or dish garden conifers. These compact dwarfs may cost more than the more common evergreens but they are so well-behaved, tidy and hardworking that they are worth the investment.