The second week of April is the time to plant cool-season vegetables like lettuce, kale, Swiss chard, radish, peas, potatoes and parsnips. You can also add blueberry plants, raspberries and strawberries to your landscape and fertilize perennial vegetables like asparagus and rhubarb.

This is prime planting time for trees, shrubs and perennials as well as a good month to renew the lawn by overseeding. Here are the most-asked questions.

Q. I want to improve my thin lawn with new seed. What is the order of feeding, soil and seeding? W.M., Sumner

A. First, rake your old lawn to remove winter debris and as much thatch or moss as possible. If your soil is well drained and not still soggy, a core aerator can be used to poke holes into the turf. Your goal is expose as much bare soil as you can for the new seed. Mow the lawn. Next, add at least a half-inch of topsoil on top of the old lawn. Follow the topsoil with a starter fertilizer followed by new grass seed. A thin layer of peat moss on top of the grass seed will keep the seed from drying out or you can invest in grass seed that has a mulch already included. If all this seems like a lot of work you can take a shortcut and just broadcast new seed on top of your old lawn, fertilize and hope for the best. Sometimes this works.

Q. When can I plant dahlias? M., Maple Valley

A. April and May are good months to plant dahlia tubers. Just be sure they have well-drained (not soggy) soil with at least half a day of sun. Dahlias produce the most blooms in full sun.

Protect the new dahlia shoots from the slugs and fertilize as soon as you see the sprouts poke above the ground. Be patient as dahlias wait until the soil is warm before they peek up above ground level and take a look around.

Q. When should I fertilize my rhododendrons? They have nice green leaves but very few blooms. T.P., Kent

A. Rhododendrons, azaleas and camellias are not heavy feeders and do not need annual feeding. For maximum flowers, rhodies need more sunlight and plenty of water in late summer and fall when they are setting flower buds. If your rhododendrons have nice green leaves I suspect they need more light. If you can, limb up nearby tree branches to increase the flower production or move your bloomless rhododendron to a brighter spot. A rhododendron that blooms early even in a shaded location is called “Christmas Cheer” and in general rhodies with darker blooms (red and purple) demand more sunlight to flower than rhododendron varieties with pale pink or white flowers.