Your late summer gardening questions, answered by an expert

CATHY WURZER: If you visit the farmers' market or even pay attention to what's kind of local there in your grocery store, you've probably seen a whole lot of cucumbers, tomatoes, and sweet corn. That's because August is high time for that produce, along with a bunch of other food, to get harvested. Meg Cowden is busy this time of the year with her enormous garden. She's back to give us tips for all of us who might have a little less than a green thumb. Meg, it's always good to have you here. How are you?

MEG COWDEN: Hi, Cath. I'm doing well. It's good to be in August. [LAUGHS]

CATHY WURZER: Yeah, but I can't believe it's already August. That's the thing.

MEG COWDEN: I know. It does go kind of fast.

CATHY WURZER: It kind of does. Yeah.

MEG COWDEN: Yeah, I'm already thinking ahead to what the F word.

CATHY WURZER: No, no, no, no, no, no, no, no, no, we don't want to start talking about fall yet. No, not quite yet.

MEG COWDEN: Oh, I meant frost. I meant frost, not fall.

CATHY WURZER: Oh! I'm not even-- you're even well beyond me. See, what's--

MEG COWDEN: You have to be. Yeah.

CATHY WURZER: What's coming out of your garden right now?

MEG COWDEN: Oh, my gosh. Just about everything. We're in between a green beans succession right now. But other than that, we had sweet corn for dinner last night with cauliflower, tomatoes, and we made baba ganoush from eggplants. We've got artichokes that have been in season for a few weeks. And that was pretty exciting. That's a totally new crop for us.

Tons of cucumbers. Lettuce is back in season. I've got some heat tolerant lettuce in the garden. I mean, kind of, you name it, it's in season. Plums and apples are also now in season, which is kind of a new thing for us, the plum tree, anyway, producing really well. So we got fruits and veggies, so I feel like it's a big success. Yeah.

CATHY WURZER: You are so successful, but is there something that just didn't quite make it for you?

MEG COWDEN: Oh, there's always something that doesn't just quite make it. So we talked earlier this year, and I was going to grow my own cumin seeds. And I started the plants probably a little too early because I tend to do that with things that I've never grown before. I always think like, well, earlier is better. And the first succession kind of fizzled out.

So then I started it again in April, planted it out, and it was in a spot of the garden that I actually ignore and with other herbs that are just-- they do their thing down there and my thyme and my oregano. And the cumin has just kind of dried up, desiccated, and is not long for this season.

So but this is the thing, is, you're going to have failures, right? I mean, you just have to know that something's going to do well and other things aren't going to do so great. My cantaloupes, they're not doing that great, but my watermelons are doing really well. Last year, my cantaloupes were just gangbusters. I had so many. I was giving them away to people left and right and just wowing them with the potency of a real, true, vine ripened, fresh, local cantaloupe. So I'm not going to be impressing people with my cantaloupes this summer.

CATHY WURZER: It's OK. You tried. You tried. Here's a question. We're gonna actually hear from some listeners in about a minute from now. Does your garden have to be all done, at least this summer crop, all done, and then you start planting a fall garden? Are you starting the fall garden already? Does that make sense?

MEG COWDEN: Yeah, yeah, that does make sense. I think it depends on what you're growing. So I do a little bit of both. So I am both eyeing crops that could be in the ground until the frost, like things like my tomatillos and my pickling cucumbers. When I feel like I've got enough jars of those canned, I pull those plants out, and that's a really great space for fall crops.

I use my onions and my garlic in the same way and my spring peas. Those are places where I know that I will have open space. I mean, right before I got on air with you, Cathy, I was out where we pulled our onions over the weekend, and I was sowing some 50-day watermelon radish for the fall garden. So I'm looking for gaps. I'm creating space on an ongoing basis throughout the summer. So I encourage people to do the same.

CATHY WURZER: OK, good to know. OK, we've got some listeners who've got questions, and they need your advice. We're going to listen to Dave's question.

MEG COWDEN: All right.

DAVE: Hi, Meg. Hi, Cathy. My name is Dave, and I live on a boat on the Mississippi River. So I only can do container gardening. I was in a terrible car accident at the beginning of the year, so I'm missing out on a bunch of gardening. And I'm hoping from here on out, I'd be able to grow something. What would I be able to grow with the remaining grow season left on my boat in container gardens? I get 100% of sun all day. Thank you.

CATHY WURZER: You're welcome. Dave, I hope you recover, too. Oh, my goodness.

MEG COWDEN: Yeah. Well, I love a gardener at heart. Nothing's going to stop Dave. So there's so much left to plant. Containers, you want like 12 inches of soil, and cilantro you can toss in pots right now. That's something that's on my list. So arugula, you could do leaf lettuce. You could try for carrots. They would probably be baby carrots at this point. Things like kohlrabi, bok choy could do pretty well here if he just directs you to that, too. So there's lots of-- I'm thinking-- so what you're hearing mostly in that, Cathy, is I'm looking at leafy greens and herbs. Now, cilantro is one of the few herbs that is actually somewhat cold tolerant, unlike basil. I mean, cilantro can last in the garden quite a while in fall, so.

CATHY WURZER: OK. So Dave has options.

MEG COWDEN: Spinach as well. Yeah.

CATHY WURZER: Oh, yeah, spinach is good, too. Yes, try spinach, Dave. Give that a shot because that's a good kind of a colder weather crop, you know. Good luck, Dave. Another listener, Meg, sent in a question. This is Mark. He said, earlier in the summer, my six-year-old daughter took a packet of foxglove seeds, put them in a pot. A few of the sprouts are actually thriving with leaves 2 to 3 inches long. I really don't want to kill our daughter's plant, which is typically what happens. So should I plan. what should I do with these now that they're able to bloom and prosper in our garden next spring?

MEG COWDEN: I would get them out of the pot and into the ground so that they will overwinter on their own. They are a biennial, and so find a sunny spot somewhere in the yard, and I would even mark them out. Make sure you don't have weeds competing with it. But get them in the ground, water them in well, and hopefully next summer, you will see those seeds really come full circle. And enjoy those foxglove blossoms.

CATHY WURZER: Very pretty. Good question there, Mark. One last question from Carrie, and we wanted to get this in because those summer tomatoes are really common for people getting into gardening. And Carrie wanted to know, do you prune your indeterminate tomatoes toward the end of the season to focus on ripening, rather than more fruit? And if so, when?

MEG COWDEN: Yes, any time right now. What is it? August 7th. I'd say, now would be a great time. I said the word already once, Cath, so I am thinking about the fall frost already, and this is a great question because this is one of the things we have to think about. Sure, there's going to be flowers at the very tips of our indeterminate tomato plants, but you've got to look down the line there, right? It's going to keep putting flowers out. That's just what these plants do. But if you really want ripe tomatoes, definitely, you can top-- it's called topping. You can top your tomato plants any time.

I also like to prune my indeterminate tomato plants down to about 3 liters. And I have a video on my YouTube page, Seed to Fork, and I show how we prune to 3 liters, which helps things feel a little manageable this time of year.

CATHY WURZER: Oh, OK. And then I just noticed this on my Twitter feed. Listener Bob wants to know how best to deal with perennials. How delicate do you have to be when dividing them?

MEG COWDEN: Oh, I might be the wrong person to answer this question, Bob, because I-- [LAUGHS] I mean--

CATHY WURZER: She's a veggie person, Bob.

MEG COWDEN: Well, no, no, but no, well, I do like perennials, too, Cathy, but my point is like, when I had perennials in our city lots, if I wanted to move my peony, and it was a 90 degree day, you know what? It was the day I was moving my peony. And it still did fine. I moved things when you think about it, is kind of my rule of thumb, which is probably not the horticultural answer. But water deeply. Water the hole before you put the plant in. Put the plant in. I mean, try to do it when it's not going to be a 90 degree day. I think we might be past those, Cathy, but I could be wrong. But--

CATHY WURZER: Right now--

MEG COWDEN: Oh, she doesn't think so.

CATHY WURZER: --there's a state fair, Meg. No, the state fair usually is--

MEG COWDEN: Oh. Oh, yeah.

CATHY WURZER: It's kind of hot.

MEG COWDEN: That's usually hot for that. Yeah, OK, well, I can wish. But I say, Bob, transplant when it's a good time for you. But do keep in mind weather. Avoid the 90s whenever possible. Before a rainstorm is another great time, you know? So you're going to get extra water.

CATHY WURZER: Oh, Meg, you are great. I appreciate it. The listeners love you. Thank you so much. Happy gardening.

MEG COWDEN: Thanks, Cath. Take care.

CATHY WURZER: You, too. Meg Cowden, author of the book, Plant, Grow, Harvest, Repeat, founder of the website, Seed to Fork, and the Modern Garden Guild. That's a gardening advice group. She is just fantastic.