when to start cleanup, houseplant watering, lily leaf beetle, adelgid: q&a with ken druse

helebore-cleanup-1IF IT THAWS outside, should I clean up now, or what if I do and then the weather gets freezing cold again? What am I doing wrong with my African violets? My friend and fellow garden writer Ken Druse and I tackled these and more of your Urgent Garden Questions on our monthly radio podcast together.

You can ask us anything, urgent or otherwise, on Facebook, or in comments on this website or on Ken Druse dot com, or by using the contact form on either one of our websites.

Read along as you listen to the February 19, 2018 edition of my public-radio show and podcast using the player below. You can subscribe to all future editions on iTunes or Stitcher (and browse my archive of podcasts here).

q&a with ken druse


how soon to start the cleanup?

Q. From Kate in the website comments: Kate is in Long Island, so in 7B. She says she is so anxious for spring. She keeps going outside to see if her hellebores are blooming. She’s been getting sporadic warm days and then going back to freezing, but on the warm days, should she start clearing some of the leaves off the garden beds or leave everything there? She’s ready to do spring cleanup, but she doesn’t want to remove some kind of warmth or protection if that’s what’s better for the plants.

Ken, I don’t suppose there’s actually a perfect right or wrong answer here, but what’s your sort of theory for this?

A. Now, you just got that question, right? You just got it.

Q. Yes.

A. It’s the beginning of February when we’re talking, so I would say leave it because the groundhog says [laughter] we’re going to have more winter. It’s funny. When the days gets warm, it’s like, “Oh, O.K., I’m ready. I’m going to go out there and start cleaning up. It’s spring.”

We could have plenty of snow, and it could be very cold again, so I would say just leave things as long as you can. As long as it doesn’t drive you insane, just leave stuff on the garden. Sometimes when you do, though, some things like leaves get kind of slimy, and it’s a drag. That’s unfortunate, but that does happen sometimes, but I’d say, if you can, leave stuff in place.

Q. One of the things, if I have cabin fever, which it sounds a little bit like Kate is anxious, and she wants to see the hellebores and stuff like that. For instance, with my hellebores, I might on a day that’s what I would call a January thaw or a February thaw, I might go out and carefully pick the matted leaves off them, because they’re going to come into bloom soon, right? I don’t want a big wads of stuff on them when they’re starting to push their flowers.

Or say I know I have winter aconite, Eranthis hyemalis [below], little tiny bulbs that are going to come in March, right? I see, oh, my goodness, a bunch of oak leaves blew in where that big patch of Eranthis is. I might do a little strategic lift, but not in general; not a wholesale cleanup. If I’m really cabin-fever-y and, say, there are a lot of leaves that scuttled into the driveway or onto the patio, I’ll do in the hardscape areas, you know?


A. Oh, sure.

Q. I’ll give myself a little chore to make myself feel better, but it’s when the lawn is frozen and/or wet or both, sometimes frozen below but mushy on top, it’s really damaging to the soil and to the grass. Do you know what I mean? It’s not good to go stomping around or pushing a wheelbarrow, right?

A. Absolutely.

Q. So we’re basically saying leave it; maybe a little tiny bit of target removal both to make you feel good, and if it’s some really early thing that you know is going to come up after a couple more thaws. Glad we figured that out, Ken.

jade plants and african violets

Q. We have a houseplant question from Gloria. She says she is having trouble with a jade plant and African Violets, two houseplants that she just doesn’t have success with, even though they’re always in those books that say these are the easy houseplants.

She assumes it’s a watering problem. She says it’s difficult to judge sort of too frequent or too little water, and she’d like to know what do we think is how she be taking care of these plants, kind of best advice? Do you grow either one? Have you grown either one? I had a jade plant, but yes. Yes.

A. I have grown both of them, and I think she’s exactly right. It’s a water problem.

Q. Always with these.

A. It sounds like too much water for both of them. It’s funny because all the books say that African violets want to be “evenly moist,” which is hard to figure out what that means exactly.  But the tendency is to over-water them because usually they’re in a very kind of soggy, peaty mix that stays wet too long and squeezes out the oxygen, and then you always get those fungus gnats. You know those little tiny gnats flying around?

Q. Yuck. I don’t love them. I don’t.

A. They don’t really eat plants, but they’re a sign that there’s decaying matter in the soil and it’s-

Q. Yes, and it’s too wet.

A. Yes. The cure for that is less water. With the jade plant, I would hardly water it all through the whole … for at least January, February.

Q. It’s interesting because I remember reading … There’s an African Violet Society of America.

A. Oh, sure.

Q. It has chapters all around the country because people show their violets, and it’s a popular plant. I remember reading a couple things about the watering, in particular, that stuck with me that I didn’t really know, but it kind of makes sense. First of all, never cold water on them, and never get water on their foliage. That’s true of the jade plants too, and that’s true of a lot of things. You really don’t want to be pouring, especially cold water, on their leaves.

For the African violets, never water from a water softener system because of those salts … These plants are in a little pot, and you get these salts building up, and it’s not a good thing. I have to have a water softener system because I have a well, and it’s just what it is, and so that’s one of those things that sometimes can backfire, and is worth looking into. Highly chlorinated water is also not good for them.

A. Definitely not.

Q. Standing in water—people leave the saucers underneath while they’re watering, underneath the plant, and then the thing stands there. That, I think, is the worst of all.

A. Yep, yep.

Q. With the jades, they’re funny because they’re succulent. They can drop their leaves. You think, oh, they don’t need water at all—like you said, in the dead of winter probably very little, but the leaf drop can happen … They can sort of sulk and drop their leaves if they get too dry. So they can get too dry, so we can under-water them even though they’re succulents.

I think that it’s important that, during active growth, which I think is in our summer months where we live, they need more water than you might … not tons, but they need more water than you might think, and you can back off in the winter. So it’s not the same watering schedule all year long with either of these, but especially the jade is what I also would want to say to experiment with.

Plus, with the jade, it really needs that sharp drainage, that sort of cactus and succulent mix kind of soil. I used to have a big old jade, and it had been in the pot a long time, and yes, it can handle it, but there wasn’t much “soil” left. It didn’t have good drainage anymore. [Laughter.] It had kind of used up the medium. Do you know what I mean?

A. Yes, I do.

Q. It could have used re-potting. It could have used re-potting so that it wasn’t sort of this nasty, funky mass of decaying roots and worn-out soil down there. That’s the other thing that I think can interfere with good drainage with these plants.

A. I think that one of the biggest problems with jade plants and with succulents kind of in general is that people get them, let’s say they’re in their cubicle in their office, and they just have a very slow death in the dark. These plants want lots and lots of sun, the most sun you can possibly give them, and they’ll look so good. Now they’re selling succulents in terrariums, which I think doesn’t make any sense at all.

Q. Oh, my gosh, what is it, like a rot-ararium? [Laughter.] It’s going to just rot in there. Oh, that’s horrible. Oh, my goodness. All right. Well, anyway, probably yes, we’re suspecting she’s right, a watering problem, so being more careful, even in the winter, because I think a lot of us do kill our plants in the winter by over-watering. Anyway, those are some tips.

starting coneflowers from seed

Q. Regina says she’s feeling adventurous. What advice do you have, and I’m saying you, Ken—you, you, you—have on starting native plant seeds for the wildflower garden? She says she tried last year with little luck at raising purple coneflower and pink coneflower. She wants to know if we have some advice? I know you’re Mr. Propagation over there, aren’t you? Didn’t you write a book about “Making More Plants”? [Laughter.] [Photo from Wikimedia via Creative Commons license.]

A. Yes, something like that.

Q. Yes, something like that. Have you started them or have any advice on, for instance, starting coneflowers from seed?

A. Well, it’s hard to generalize. I’m sitting here thinking of generalizing, because seeds like purple coneflower, those are usually kind of the easiest seeds to start, the ones that are little dry seeds that are dry on the plant, and you just sort of sprinkle them almost on the surface of some medium, and they’re up in like three weeks, if you want to do it now, and they’re under lights for like eight weeks. You can also direct-sow them outdoors, and you can do that either in the fall, or you can do that in the spring as soon as the soil’s about 65 degrees or warmer.

They should be pretty easy, so something happened, I’d say. Also, when you buy the seeds like that, if you’re buying them from a reputable source, they’ll usually have some direction on the seed packet, but those shouldn’t be too challenging.

Q. You were saying if you started them now under lights and so forth, but would they have had any winter requirements and so forth? I don’t know with coneflower.

A. Well, if you picture them outdoors, they’re going to be cold.

Q. Yes.

A. Generally, those seeds and ones like them need to be dry during the winter. Most of the places that you buy them from like Prairie Moon Nursery or something like that, they’ve stored them cold and dry.

Q. I see.

A. When you get them, when you buy them, and you’re going to start them later, not right now, but closer to when they’re going to go outside, like eight or nine weeks before they go outside, and then they have to be hardened off and all that stuff, but they’re going to be ready, and they’re going to come up.

Q. O.K.. You’re promising?

A. Yes, I’m promising. [Laughter.]

Q. O.K.. Good. Well, and you mentioned a great place, actually. Prairie Moon Nursery does have great cultural tips down to the species level, for all of the prairie-type plants that it does sell, the wildflowers that it does sell, so that is a great place also for Regina to look for more information on them. [Also check coneflower germination guidelines on the Johnny’s Selected Seeds website.]

when to start vegetable-garden seeds

Q. Mary Ann also has a seed question. It’s more general, and it’s for the vegetable garden, and she saved some seed and in general, the thing that she says is every year it’s like her problem’s remembering when to start the seed and, of course, which needs how much light and which needs warmth and which needs whatever.

Generally speaking, when to start what is this mathematical equation that starts with in our temperate zone in our spring sowing things or late winter sowing things to grow in the summer in the vegetable garden. It starts with knowing what your frost date is, obviously, right, your final frost date?


Q. Then you say, oh, O.K., this thing needs six weeks indoors under lights, and it can go out two weeks after frost, or it can go out at frost time. If it can go out at frost time but it needs six weeks indoors, you back up six weeks, and that’s when you sow it.

It’s a mathematical equation about the frost date, and the time needed, and the time before or after that frost date that thing can go out into the indoor environment and be transplanted, so that’s how you get your equation.

I mean I know that I’m speaking the obvious to everybody who’s listening, but I forget, too, right? And so to make it easier for myself, years ago, I started lumping things, thinking of groups that I could lump together, plants that I could start at the same time inside and put out at the same time, roughly speaking, so that I wasn’t trying to memorize 15 different things.

I was sort of having three groups, my cool-season growers, my sort of extra-cool and extra-long ones like, say, onions and leeks, they are sort of extra, extra early, but then Brassicas and other cool-season things, some salad-y things that can go out relatively early, and starting those at one time and then transplanting most of them around the same time. And then my warm-season things: my tomatoes, my peppers, my eggplants. I might hold some a little longer in the house, an extra week or two, but I sort of lumped them and started them all at the same time.

Anyway, long story short is that to make it easier for myself, I selfishly had a friend program for me a sort of a calculator tool, my seed calculator tool on the website, and it has all of the most popular vegetables, herbs, annual flowers. You just put in your frost date. You just pick your frost date, and it’ll calculate it for you and tell you when, and how long inside, and when to transplant relative to your frost date.

A. Oh, that’s great.

Q. Yes, so it’s like bing, bang, boom. Don’t feel bad, Mary Ann, I had to build myself a calculator tool to remember. [Laughter.]

A. [Laughter.] Well, Margaret, how do you find out, if you don’t know what your frost date is, how do you find that out?

Q. That’s what Google’s good for, right? Some of the companies like the almanac, The Farmer’s Almanac or whatever it’s called, and I think maybe Dave’s Garden website, that sort of community-based website, and Victory Seed, and a number of other places. That’s what the Google search will yield you is a calculator for that, and it’s based on National Weather Service kind of information. Yes, it’s frequently Zip code-based; you just tell your zip code. That’s a pretty easy web search.

Of course, they seem to have shifted a few days here and there over the years, not that anything’s different outside…

A.    [Laughter.]

Q.  …not that things are changing. [Laughter.] O.K., change the subject.

fighting lily leaf beetles

Q. Chris wrote in with a question about lily leaf beetle. Do you have those, Ken?

A. Oh, my gosh.

Q. I guess that’s a yes answer?

A. I was so lucky, and I didn’t have them, and people were complaining about it, and I didn’t know what it was, and it came down from Canada. Well, about, I think two years ago, they appeared. Well, I guess it was three years ago they appeared. The next year, I had no lilies.

Q. Yes, me too.

A. Gone.

Q. Me, too.

A. Then, the year after I started dealing with it, which was hand-picking them religiously, and the lilies did come back a bit, but it’s horrible. What do you do?

Q. A few months ago, and I don’t remember exactly when, but within the last six months to a year, I did interview an entomologist at the University of Rhode Island, Lisa Tewksbury, to ask her about this. URI is one of the universities that’s been working on this problem because the Northeast is a place where there’s been a concentration of difficulties with the lily leaf beetle, which is an alien pest from elsewhere that got accidentally imported.

A. They’re lacquer red, we should say.

Q. They’re very beautiful. They’re scarlet red. They’re very beautiful, but they’re very gruesome and bad, naughty, naughty. URI has a biological control lab where they’ve worked on identifying and developing protocols for using natural enemies of imported pests to defeat imported pests. We talked. I’ll give everybody a link to that conversation because she, obviously, is the expert, and I’m not. They did, through a very long, government-approved process, identify natural enemies of the lily leaf beetle from its areas of origin and did get approval, eventually over a number of years, to begin using some of these parasitic wasps to infect, hopefully … to release and infect the lily leaf beetles and unhinge them. [Laughter.]

In the late ’90s or 2000-ish, 2001, there were some of the early releases. I think they did the first ones in Boston, and there were more around New England, and that’s really been going well. I think Canada just did its first releases of this parasitic wasp, this natural predator of the lily leaf beetle, a few years ago, and I believe that URI is coordinating with other states to do so. There is hope, but meantime, really, what you said, Ken, is what we need to be doing, which is if you just have a few lilies in your backyard, you’re going to hand-pick the adults.

They overwinter as adults, and the time that they’re going to emerge somewhere near the lily plants is when the lily plants emerge because that’s what they’re going to be on, and feed on, and so forth, and reproduce on. That’s their plant. As soon as it’s coming up, you’ve got to be out there looking, and you’ve got to squish, and squish, and squish, and they’re going to make these horrible … They’re going to lay eggs, and you go to look underneath for the lines of the tiny little bright-colored eggs in a line and all that kind of good stuff.

Neem oil, which is not a broad-spectrum, very, very harmful kind of substance to use, is a good material, Lisa Tewksbury was telling me from URI, and safe to use. So that’s another thing that you can do is to use neem oil and hope and hope and hope that the benefit of these biological controls spreads to your area, because it is a very, very, very tricky pest. [A link to the full lily leaf beetle interview.]

woolly adelgid and wood mulch

Q. We had another imported/introduced pest issue question from Laura, which was a mulch question. This was interesting. She said, “Hemlock mulch is available in my area. The hemlock trees around here already have some wooly adelgid.” You know what wooly adelgid is, don’t you, Ken? [Adelgid on hemlock twigs, above, from Wikimedia by Nicholas A. Tonelli.]

A. Mm-hmm.

Q. Yes, a terrible little imported pest that’s been decimating the Eastern hemlock forests. So she wants to know would using hemlock mulch increase the problem? Do you have quarantines—I don’t think in New Jersey you do against the transport of wood materials like firewood and mulches and so forth around the state or from state to state. Do you have that? In New England states, we have a number of states that have such quarantines because of the idea of potentially moving around these pests. New Hampshire, Maine, Vermont, they all have rules against moving wood materials to try to minimize this kind of problem.

A. No, I don’t think so, but I remember with the Asian longhorned beetle, you weren’t supposed to move anything in New York City, where it started.

Q. Yes.

A. Just in general, I think better safe than sorry.

Q. I totally agree.

A. You think that mulch is all … especially with hemlock, it’s usually ground up very fine, so you wouldn’t think anything could survive there, but who knows, and why take a chance? It’s probably best not to use it.

Q. Yes, and I remember when-

A. Besides, who needs wood much? I’m sorry to bring that up right in the middle of everything, but that’s like … we don’t need wood mulch. There’s not really any wood mulch in nature. There are other things that make better mulches, like chopped-up leaves, and oak leaves are great, the best, and you can topdress with compost and things like that. That’s a whole other story, but I’m sick of seeing wood mulch [laughter], aren’t you?

Q. No, I know.

A. Wouldn’t you rather see groundcovers?

Q. I know. Yes, I agree with you. I’m not a big user of wood mulches except on pathways and so forth.

I remember reading—and I want to say it was the University of Massachusetts, when I was doing a different story about adelgid—I think they feed on the twiggy areas, so theoretically the parts that are going to be ground up for mulch is more the trunk, and large branches, etcetera. So theoretically … and then there’s the timing, the time of year that you would or wouldn’t have their presence and da, da, da, da.

The thing is, especially with fresh mulch, I wouldn’t move it. I wouldn’t want to move fresh woody products anywhere, anytime for the fear of introducing anything, whether adelgid or otherwise. You could probably get away with it without increasing your risk of adelgid, but why would you risk it? I agree with you, better safe than sorry. Better safe than sorry, for sure. [Note: The UMass factsheet about adelgid that I referred to is at this link.]


‘the horrors of clay soil’

Q. So maybe, real quick, just one last quick little thing. I know we could talk for an hour about this one, but Wareen on Facebook wants … Her question is, it’s actually in quotes: “The horrors of clay soil.”

A. Whoa.

Q. [Laughter.] What’s the antidote, Ken?

A. Well, the antidote? The antidote for clay soil is the same antidote as the antidote for sandy soil. Which in both cases is to add organic matter.

If you have a really bad clay situation, you can also work some gravel into the clay soil if it’s really bad, if it’s the kind of soil that gets rock-hard when it dries out, and it’s hard to re-wet, and then it’s sticky and slimy when it’s wet and stays wet forever.

Or maybe pick the plants that really would like that. There are some plants that would like that. I’d say same answer for sandy, fast-draining, and for clay soil that keeps the moisture too long, which is to add more organic matter, and we like compost and plenty of it.

Q. Compost, compost, compost, and then some more compost. [That’s Margaret’s 40-foot-long compost heap, above.]

A. Then what?

Q. Compost.

A. Compost. [Laughter.]

Q. [Laughter.] Yes. Ken, thank you very much for helping us squander yet another urgent garden question session. I hope all is well, and I’ll talk to you soon, yes?

prefer the podcast version of the show?

MY WEEKLY public-radio show, rated a “top-5 garden podcast” by “The Guardian” newspaper in the UK, began its ninth year in March 2018. In 2016, the show won three silver medals for excellence from the Garden Writers Association. It’s produced at Robin Hood Radio, the smallest NPR station in the nation. Listen locally in the Hudson Valley (NY)-Berkshires (MA)-Litchfield Hills (CT) Mondays at 8:30 AM Eastern, rerun at 8:30 Saturdays. Or play the February 19, 2018 show using the player near the top of this transcript. You can subscribe to all future editions on iTunes or Stitcher (and browse my archive of podcasts here).

      1. margaret says:

        You are right, Liz. I thought I had divvied up the questions so we’d have equal ones to tackle, but I totally screwed up. I will try to shut up next time!

  1. Elaine says:

    Here in southern RI we’ve seen a noticeable decline in the lily beetle population. Still hand pick but we find very few. Thanks URI!

  2. CIndy Donahey says:

    I am going toplantfireweed. There was a mattress fire, all the way down to the ground, in a bad place across the road from an old landfill I own. The EPA lady mentioned it to me and I gritted my teeth.. It is a clump forming plant. I am going to burn a place in the garden as well. There is some scraped landanother place and I am going to toss some mullein, a variant, seed down. I don’t have a car so I can’t always get down. The landfill surrounds the highest point in Hocking County. I stllhave wild roses, blueberries and other wildflowers despite the remediation.

  3. Ann M. says:

    Gardening in Central Florida, is challenging! Makes me realize how much I have to learn about compost and nativars! Thanks for every word!

  4. Doreen & Leo says:

    My husband and I really enjoy your most helpful podcasts and especially the ones with you and Ken.
    Our daylilies are beginning to break ground now and it’s only February. Is there an organic way to
    keep the slugs from chewing on the tips of our plants?

  5. Judith Gale says:

    Hi Margaret and Ken
    speaking of Neem Oil I have been told it’s the best thing for rose black spots what do u two think. I live in nyc (manhattan would u believe)Also how much compost should I use in my zone 7 soil. I remember being told too much compost is not good?
    I really enjoy your podcast
    Thanks so much for your help
    Judith Gale

    1. margaret says:

      Hi, Judith. I believe Neem can act as a preventive for blackspot more than a curative, because it makes the leaf surface inhospitable to the spread of fungal spores as I understand it. The idea would be to spray every 1-2 weeks starting well before the season for the fungus typically begins, according to label directions.

      While it is possible to have too much organic matter (here is why explained), it would take some doing if you are starting with what is probably mostly rubble and who knows what in a Manhattan location. If I were starting to up my garden game in such a location, I would start with a soil test (full analysis not just pH)and go from there, and probably be purchasing both clean topsoil and compost to amend the intended beds. The soil test will tell you a lot.

  6. Cenepk10 says:

    My question: what to do about squash bugs. Barely harvested any squash last year – It was a virtual infestation ! Outside of Atlanta here – very warm – I untied the patio umbrella & voila ! Wasps & squash bugs !!!! Alive, btw.

  7. I like Prairie Moon Nursery for seed germination instructions but I especially like Jelitto.com and tomcothier.com. However all three of these sites are for ornamentals, not veges. Sometimes these sites do not agree and then I do the most complicated one. If the seeds germinate before they’re “supposed to” so much the better.

  8. Julie Bruning says:

    In response to ‘the horrors of clay soils’ I would recommend reading ‘The Intelligent Gardener” by Steve Solomon (founder of Territorial Seeds, food gardening 35+ years). Too much magnesium in relation to calcium in acidic soil results in clay-like soil. Solomon recommends testing your soil and then using those results to make necessary adjustments. Excess magnesium is often the result of using too much dolomite lime which many gardeners dealing with acidic clay soils in my region (Pacific Northwest) use regularly and often without consulting proper application rates.

  9. Judith says:

    I gave up growing lilies because of the infamous lily beetle, but they also attack the snakehead fritillaries. Not willing to give those up I have tried using Neem oil spray with some success ( or knocking the critters into a small bucket of soapy water). Vigilance is the key!

  10. Tibs says:

    It was in the 40’s and not raining and I got the tidy bug bad. I was a good little gardener and only raked the devil strip of the crud dumped by the snow plow.

  11. Julie says:

    Hello Margaret and Ken,

    We had a horrible wildfire (Utah Z6B) that burned about 500 scrub oak trees and various fruit trees and ornamentals in our yard (house spared!). We’re going to take down and hopefully mulch most of the dead trees, but where to begin with the charred soil? It was so rich from years of leaves. I’d love to have plant something that would choke out all the noxious weeds that burned. Thanks!

  12. Dahlink says:

    We have two composters, but after seeing the photo of Margaret’s 40-foot long compost heap, I have serious compost-envy!

    We have a great-niece named Lily, so I have been adding more lilies each year in her honor. Hope the bad bugs stay away!

  13. Jean C. says:

    After reading this post, I feel marginally better about not going out to the garden and doing a major cleanup right now. And it was a good thing I didn’t. We had a real warmup in Boise, Idaho and now it’s freezing and snowing again. So most of the leaves and plant rubbish will stay for now. I did read somewhere that it’s best to leave plant matter till spring because it does provide some shelter and food for critters (the ones you want in your garden, that is.) Great post!

  14. Cindy says:

    Naturally decayed wood was once used as a mulch. Gardening wise, it was combined with sand, pebbles or shells etc. It comes in many different textures and colors ranging from black to putty to reddish brown. At one time, fallen naturally decaying trees were everywhere. Running a shredder thru the roots of a timbered tree Sort of approximates. Better for wildflowers than vegetables. Some federal forester sent me a whole packet on what he called rotten wood, crumble was new to him. This info is lost. Wild orchids were huge weeds and there were attempts to add bird dropping substitutes to get big orchids. Someone I knewfed their dogs corn dodgers and something else. Wildflowers gardeners were secretive.

  15. Lauren says:

    Oh boy Lily Leaf Beetles came and were eating all my Oriental Lilies so I got really good at picking them off fast so they couldn’t hurl themselves upside down into the mulch. I would spend the better part of every day picking since I had lots of lilies. They also liked Trycirtis. In my new house I will not grow these until the wasps have stepped in. Too aggravating.

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