Garden guru’s tips on pruning, insects and having your flowers and eating them too

The third week of May is the time to groom your spring flowering bulbs by cutting off the faded flowers and stems or digging up past-their-prime tulips and let them dry out in a hidden spot for replanting come fall.

You also can cut back your sedum “Autumn Joy” so the new growth is just a few inches high. This will ensure shorter plants with more branching that will not flop to the ground when in flower. You can do the same pruning to tall phlox and pinch back leggy petunias and other branching annuals and perennials.

Got houseplants? This is the week to move them outside if you have locations protected from the afternoon sun. Plants get sunburned just like people, and after a winter indoors, they have no resistance to direct sun when first placed outside.

Q. My lilac is done blooming. Do I prune it? What about rhododendrons? — T., Tacoma

A. Yes, if you want to. You can prune lilacs and rhodies after they flower if you want to encourage more bushy side growth. Lilacs in Western Washington can be thinned out by removing weak or crossing branches and by cutting the oldest stems or trunks close to ground level. This gives the younger side shoots a chance to take over.

A better lilac to look for at nurseries this month is the dwarf “Miss Kim” or one of the reblooming lilacs like “Josie” that flowers twice a year. Why grow lilacs if you can’t reach the blooms to smell or bring indoors?

Tip: Plants that are labeled as dwarf may not be as compact as it says on the plant label. Due to our mild weather in Western Washington, most evergreens and shrubs grow much larger than what the plant label will indicate. Give dwarf conifers, dwarf lilacs and dwarf fruit trees plenty of room.

Q. Every year my cabbage and broccoli get small green worms. Any suggestions? — P.S., Buckley

A. Yes! This is the week to stop the white cabbage moths from laying eggs on your cole crops. (Cole crops are members of the cruciferous vegetable family such as broccoli, cabbage and cauliflower.) A floating row cover over the young plants will keep the butterflies from landing with their eggs. Nurseries and garden centers sell these spun polyester coverings under the name of Agricultural Fleece or Remay. These lightweight “blankets” allow sun and water to pass but are a physical barrier from many flying insects. They can be stored away during the winter and reused for several years.

Experienced gardeners also know that soaking a head of cabbage or broccoli in salted water after harvest will cause any insects to float to the surface.

Q. I am interested in edible flowers. I know about nasturtiums and violet but what do you think about the new edible rose from Proven Winners? I saw it at a local nursery. Will it survive in our area? — R.Y., Olympia

A. You can have your flowers and eat them too, as the newest edible shrub to plant is a rose called “Flavorette Honey-Apricot” and it is considered a culinary herb. This rose survived the winter well in my Western Washington garden and the pale apricot-colored petals have a sweet, rather fruity taste. It was bred to be used in deserts, salads and infusions. This edible rose grows to 4 feet tall and can adapt to containers but needs at least 6 hours of sun to flower well.

See Marianne this month

Marianne Binetti will speak on Edible Gardening at 10 a.m. Saturday, May 25, at Windmill Gardens Riverside Farms, 8217 Riverside Drive E., Sumner.

Marianne Binetti has a degree in horticulture from Washington State University and is the author of several books. Reach her at