Gardeners ponder plants as fall approaches

September 12, 2012 

With summer soon to be a warm and distant memory, readers begin to ask all sorts of questions about gardening in the shifting season. In today’s column, find advice for contending with tomatoes that don’t ripen before the frost, rampant mole activity and when to plant winter pansies for color in your garden.

Question: Will my green tomatoes turn red before frost? Will cutting off the new blossoms make the green tomatoes ripen faster? Any tips would be appreciated. — C.M., Olympia

Answer: Yes, some of your green tomatoes will turn red before the end of the month – those with a dark green spot or star on the blossom end of the fruit will continue to ripen and color up if you bring them indoors or leave them on the plant but protect from the frost. Late summer and early fall is a good time to snip off any new flowering branches on your tomato plants and remove any hard, light green tomatoes that have no chance of ripening.

You want your plants to put all their energy into ripening the fruit already formed, not into growing new tomatoes that will not survive the winter. Be sure to keep the leaves of your tomato plants dry if you want to protect them from the late blight. Wet foliage encourages this fungus among us, turning stems, leaves and then the entire plant dark brown. Tomato blight moves quickly, so harvest any green tomatoes at the first sign of dark, rotting leaves

Do moles eat geraniums? I have a row of geraniums in my front yard and they are wilting even though they get water. I do see that a mole has tunneled in the area. I have grown geraniums for years and never had them wilt like this. We do have a lot of mole activity this year. — J.B., Auburn

Moles eat insects, mostly earthworms. But they are probably at the root of your problem. Their runway could be disturbing the root system and causing the wilted leaves on your geraniums. Another possibility is that a vole or field mouse is using the mole runway as a super highway to an underground restaurant. Voles feed on bulbs and roots, especially in the fall. Use a mole trap to control the moles and a mouse trap if you think you have voles. Both types of traps are sold at garden and home centers. Push your wilted geraniums back into the ground after soaking the soil to collapse the tunnels. You might be surprised with another few months of outstanding bloom. Geraniums are survivors and often flower more intensely when stressed out by lack of water or root damage. This explains why geraniums grown in small clay pots seem to pump out more flowers than lush green geraniums with rich soil in the ground.

When can I plant winter pansies? My petunias did not do well while I was gone on vacation. I want to rip them out and replace them with those wonderful pansies that seem to bloom all fall and winter. — P., email

Yup, petunias are pansies when it comes to weeks of vacation neglect, but pansies are tough when you plant them in the fall. The time to plant pansies, heucheras, asters and mums for the second act is any time during the months of September and October. Now here’s a tip for spring color. After you pull out those pouting petunias but before you add the pretty new pansies, slip in some spring-blooming bulbs. Crocus, daffodils and tulips planted in the fall will put on a splashy big show in the spring – and you can plant your pansies right on top of the bulbs. If our winter is mild, the spring bulbs will push up through the still-blooming winter pansies, and you’ll have a double show of color in the garden.

I enjoyed your talk at our local nursery. My question is why did you recommend using white winter pansies for pots on the porch? I know you gave a reason, but when I came home with a flat of white pansies my husband asked me, “Why of all the colors did you choose white?!!” I know you had a good reason for this suggestion … . Help! — W.R., email

You mean hubby has not heard that white is the new black? I think I might have recommended white flowers to brighten up dark porches and entry gardens and for gardens where the owners work during the day. White flowers show up better at night, mix well with all other colors and really give a formal look when used to fill dark urns or ceramic containers. One more reason to wave the white flag – your winter pansies will be blooming in December if you grow them in pots under the protection of a porch roof. Then, you need only add some sprigs of holly or a branch of red berries to your pansy pots and you’ve got the easy answer to outdoor Christmas decorating. Now that alone should make any light-stringing husband love white winter flowers.

Marianne Binetti has a degree in horticulture from Washington State University and is the author of several books. For gardening questions, write to her at P.O. Box 872, Enumclaw, WA 98022. Send a self-addressed stamped envelope for a personal reply. She also can be reached at her website, binettigarden.com.

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