Q & A: Vegetables

green tomatoesGot a gardening question? Ask Susan! What follows are 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.

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 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. I was wondering where you get all your seeds. I have looked at NW Seed and cannot find a lot of the seeds you listed in the paper. JD, Spokane

A: While I do order a lot of them online, I stay in touch with the gal who orders the seeds for Northwest Seed & Pet’s Sprague & Altamont store. She does a great job of ordering the ones I write about. If you can’t find them there, do a web search on the name of the variety to see who carries them.

Q. Do you rotate (the plantings in your) beds every year or use the same ones and amend the soil yearly?

A: Yes, I am very careful to rotate what’s planted in the beds (by plant family) to cut down on the chance of insect and disease problems. I also amend the soil yearly, based on what will be growing in each bed. For example, if onions or other root crops will be planted in a bed, I add bone meal to the soil to increase the amount of phosphorus to help with root development.

Q: Could you write about the difference between hard- and soft-neck garlic? There are so many choices out there – what should we look for in our area? RM, Spokane

A: My husband is a garlic aficionado and plants our garlic every year. He prefers hard-neck garlic, specifically ‘German Red’ and ‘German Porcelain’, because they have large cloves. You can’t braid together hard-neck garlic, though, so if that something you want to do, you would go with a soft-neck variety. Bill says that ‘Inchelium’ is the go-to variety for soft-neck. It has small cloves, which works well for recipes that call for small cloves.

Q: I’m growing onions for the first time this summer. My Walla Walla Sweets are ahead of the red and yellow as their tops are drooping over. I gently fingered the bulb part and they are a somewhat smaller than a tennis ball. Maybe like a big golf ball. So is this the time to reduce watering? Will they continue to get larger? BN, Coolin, ID

A: When the tops flop over, that’s when you should stop watering them. Just pull up the bulbs and leave them on top of the soil to dry out a bit. If there’s the threat of rain, move them to a protected area so they won’t get wet. You’ll want to use up the Walla Wallas first since they don’t keep well. The red and yellow varieties will take a bit longer to mature than the Walla Wallas. If all 3 types of onions are growing in the same bed, though, I wouldn’t cut back on watering the reds and yellows. If the WWs haven’t completely fallen over, keep watering them till they do.

Q: How can you tell when your watermelon is ripe, what’s the trick? KW, Spokane

A: I’ve heard that the area of the melon that was lying on top of the ground turns yellow when it’s ripe. I’ve heard other people swear by “thumping” on the melon; if it sounds kind of hollow, it’s supposed to be ripe. Those are the only 2 methods I know of!

Q: My ‘Early Girl’ and ‘Sweet 100’ cherry tomatoes are growing a bit wild,
bushy and about 4-5 feet tall.  Should I snip the new shoots to
channel growth into the green tomatoes I see? JT, Spokane

A: I usually don’t start trimming my tomato plants back until the first week of August. I just shorten the plants a bit with the first pruning. Then I’ll do another pruning about 2 weeks later, removing a bit more. And then in Sept., I really remove a lot of growth so what’s left are the branches with the tomatoes on them, pruned right above. I think you can coast a bit longer before “terrorizing” your plants!