Q & A

Q&AGot a gardening question? Ask Susan! What follows are the 10 most recent reader questions. Each time a new one comes in, I’ll add it to the top. To ask a question, drop me a note at Susan@susansinthegarden.com.

To view the Q&A by topic, click below: 


Q: I’m very interested in the insect hotel & mason bees. Unfortunately we
are cursed with lots of wasps and I’m allergic. I fear the wasps will
take over the hotel and I will just have made my problem worse. Any

A: We feared the same thing so here’s what we did: We filled each section of our insect hotel from the bottom all the way to the top so there wouldn’t be a “ceiling” for them to hang a nest on. We do have a lot of wasps in this area yet they haven’t been a problem in the insect hotel at all. And I’m guessing it’s because we packed it with materials.

Q: Thank you for all the great gardening tips.  Today’s article raised
the following questions:  I have a banner crop of sweet onions.  I
pulled them today and will let them dry.  Do I allow the tops to dry
to the point of falling off?  Where and how long will they store?  I
also have butternut squash for the first time.  Like acorn can they
remain on the vine until frost? JR, Spokane

A: Onions: when you say sweet onions, I’m thinking of varieties like Walla Walla and Yellow Sweet Spanish. If it’s the former, it will only keep for about a month. If it’s the latter, it should keep for about 4 months. So it varies, depending upon the variety. You want to dry them until the stalks and outer skin of the onion are completely dry and papery. Then you can safely cut off the stems and store them. I would keep them in a cool, dark place such as a basement, garage or closet. Squash: You should be able to leave your butternut squash on the vine until it frosts. They can usually handle a light frost but I would keep them out for a heavy frost as that can damage the skin and flesh of the squash, thereby affecting its storage potential. If you saw my video today, you know about the “thumbnail test” to determine if a squash is mature. If you haven’t seen it, here’s a link: Everyone Can Grow A Garden #27: When to Harvest.

Q: I am desperate to find an organic way to rid my apple trees of codling
moths. This year, we lost our entire bumper crop of apples from four
trees to these insects. We have no leaf litter; I hung 25 plastic balls smeared with the Tanglefoot sticky substance purchased online, and put Tanglefoot paper bands around the trunks smeared with the sticky substance, all to no avail. Any suggestions? DC, Santa Fe, NM

A: In June, I wrote about what my husband and I do to grow our apples organically in the following blog post: Growing Apples Organically – 2017. However, I have some more recent information to share with you: A reader sent me a response to that post, indicating that she has been using codling moth attractant and has been getting about an 80% success rate of worm-free apples. She had asked if I thought she should also put on the nylon footies (refer to my blog post) to get 100%. My response to her was that if she’s only doing the attractant and getting 80% success, I wouldn’t bother doing anything else! So my husband and I have decided to try using the attractant as the only method of codling moth control on 1 or 2 of our apple trees next year to see how well that works. You can bet I’ll write another blog post about that! To learn more about apple codling moths, I have a new Organic Pest Control guide on my website. There is a page specifically on apple codling moths, to give you a good idea of their life cycle, etc. And there is also an information page on the apple codling moth attractants. They are homemade and one of the most important ingredients is molasses.

Q: About 2 months ago, I planted a packet of Ed Hume “French Cinderella” pumpkin seeds in my garden on the South Hill.  Lovely vines sprouted with multiple yellow flowers (which hosted bees aplenty). I have only one well-developed pumpkin, about ready for harvest.  I’m hoping 2 babies will keep on maturing.  Otherwise, I can’t understand why most of the flowers dried and shriveled on the vine.  Can you figure why so few developed? Earwigs? Heat?  I didn’t over-water or fertilize. M, Spokane

A: I think there were two big challenges this season: heat and drought. It sounds like the latter wasn’t a problem since you were good about watering your plants regularly. But 
when it’s so hot for so long, plants that need to flower and set fruit just don’t function normally. It doesn’t sound like a pollination problem to me, since you commented on having so many bees on and around the flowers. So I would have to say that the heat may have caused primarily male flowers to bloom, and perhaps not so many female flowers. If that was the case, then the flowers that dried and shriveled up were male flowers 
and pollination didn’t take place.

Q: I planted a 12 foot row of turnips and another one of spinach in the same raised bed in May, separated  by 12 inches.  I got no usable items from either.  The turnips were full of small worms.  It was not like an onion or radish that might have a small hole that you cut away to use the rest.  It was totally unusable.  The spinach, rather than making leaves that we eat, grew tall and flowered. SS, Spokane

A: Regarding the turnips, it sounds like they had root maggots in them. Next time you grow them, you might try covering them with some floating row cover as soon as you plant them in order to keep the adult fly from laying its eggs on them. There is an information page in my Organic Pest Control Guide that explains how row covers work. Regarding the spinach, it could be that the weather was just too darned hot for them. Spinach is a cool-season crop, so it’s best to grow it in the spring or fall. When a plant creates flowers, that’s its way of making seed so there will be a next generation… and it certainly sounds like the heat caused the spinach plants to bolt to seed.

Q: I planted a trumpet vine 3 years ago. I unfortunately fertilized it in the first year, thinking that it would produce more blooms. Instead I got beautiful, thick green leaves. I have not fertilized it since the first year, but it still has not produced flowers. It is beautiful and has healthy foliage. Will it ever bloom or should I dig it up? PA

A: That’s frustrating about your trumpet vine not blooming yet. It’s true that if you put a nitrogen fertilizer on a plant that needs to bloom, it will encourage more leaves than blooms. As long as it’s in a sunny spot and is getting regular water, it sounds like you’re doing the right things. I did find information online that says a trumpet vine can take up to 5 years to bloom, so I would skip the fertilizer and see what happens in the next year or two.

Q: My wife and I enjoyed the recent video tour of your garden. I noticed you use a red weed barrier covering for one of your raised beds. Why red? And where did you get it? JP, Spokane

A: It’s called red plastic mulch, tomato mulch or “SCRM” mulch. It serves 2 functions: it is a part of the color spectrum that reflects the maximum amount of sunlight up into the plant, and it also increases the soil temperature. I primarily use it on my tomato bed, but also like to use it for growing melons, peppers, eggplants and winter squash. When I switched from using black plastic mulch to red, I easily had about a 30% increase in the plants’ productivity, which was very impressive! So I’ve used it ever since. This year, I’m also testing a green-colored mulch just to see how it performs. You should be able to locate the red plastic mulch locally, at a well-stocked garden center such as Northwest Seed & Pet in Spokane. Online sources include: Lee Valley.com, HarrisSeeds.com, JohnnySeeds.com and GardensAlive.com.

Q: Susan, do you know of any organic spray to stop leaf miner activity?  I forgot to put a floating row cover over the pony-pack of chard, and now the leaves are being eaten up one at a time. TM, Spokane

A:  That’s a shame! I don’t know of any organic spray that will work, esp. since the leaf miners are in between the cell layers of the leaves. Maybe you can pull off the infested ones, cover the plants, and see if they’ll do OK from that point on? And for next year, be sure to use a floating row cover as soon as you plant your chard (or spinach or beets, for that matter) so you won’t have to deal with those pesky insects.

Q: I just planted my tomatoes last week and have floating row cover on them.  How long should I keep it on? RM, Spokane

A: To give my warm-season crops a nice start, I like to cover them with floating row cover right after transplanting them into the garden. I leave it on for 2 to 3 weeks, depending on what the weather is doing. But for any of these crops (melons, cucumbers, pumpkins, winter squash and tomatoes), the cover needs to be removed when they start blooming so the pollinators can get to the flowers.

Q: I planted five plants in a 12 foot x 4 foot raised bed last year, ten
inches high.  This year they are growing out of the base ground around
the bed.  Why do they grow down, and move away from the bed and
reemerge in the gravel walk?  Darn plants anyway.  I am cutting them
at  the ground level outside of the bed to control them but I do not
know if that will help. SS, Spokane

A: No worries, this is what raspberry plants like to do! They send up runners here and there occasionally, I guess as a way of propagating their species. I get them, too, and I just pull them up out of the ground, roots and all. However, if you need more raspberry plants, you could gently dig them up and put them into your “official” raspberry bed!

Q: I don’t understand what half strength dilution means referring to the
fish fertilizer.  Could you tell me how much to use per gallon of
water? OLR, Spokane

A: When I fertilize young seedlings with fish fertilizer, I like to use it half-strength to avoid burning or overfeeding them. This means using half as much fish fertilizer from what is recommended on the label. So, for example, they recommend 2 tbsp. of fish fertilizer to a gallon of water for vegetables, bedding plants, bulbs and annuals. That means I will use 1 tbsp. of fertilizer to a gallon of water.

Q: Can you tell me where we can purchase a copy of your book? 

A: Thank you for asking! There are several places where you should be able to locate Northwest Gardener’s Handbook: 1) at the Spokane County Master Gardener’s plant clinic, located at 222 N. Havana St. (just south of the Indians Ballpark). They are open 9-3 Mon-Thurs, 9-1 Fri and 9-12 Sat. Their phone number is (509) 477-2181; 2) at Auntie’s Bookstore downtown; 3) at Barnes & Noble (either Northtown or east of the Spokane Valley Mall) and 4) On Amazon.com.