replanting after removing the invasives; bulbs in pots; garden-tour prep: q&a with ken druse

WHAT TO PLANT (OR DO) NEXT, after you remove invasives like garlic mustard? How to grow bulbs such as pineapple lily (above) in pots year to year? What are the pros (and cons) of hosting garden tours? Time to tackle some of the pile-up of Urgent Garden Questions you’ve been madly posting in blog comments, on Facebook, and in emails, with help from Ken Druse, in Part 2 of the monthly Q&A episode of my public-radio show and podcast.   

My longtime friend Ken, an award-winning garden photographer and author of many books, including “The New Shade Garden” and “Making More Plants,” produced his own “Real Dirt” podcast for 10 years, all available on KenDruse dot com.

Read along as you listen to the May 15, 2107 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).

The May show is a doubleheader; this transcript is the “overtime” segment, starting at about 24 minutes into the audio file, and Part 1’s transcript is at this other link, including how to work around wet spring soil without damaging it (or crushing desired self-sown seedlings), what to do about moles, or voles in the garden (and how to tell them apart), and more.

may q&a part 2, with ken druse



Q. Are you still there, Ken, or did you go outside?

Ken. I’m still here. [Laughter.]

Q. I have to tell you, my tractor had a nervous breakdown—the first time in all the years I have had it that this has happened. And I’ve got some serious turf to mow, and it’s getting pretty bad. I call every day to the repair place, “Is it fixed yet?” And they say, “Sorry, we have a lot of farmer emergencies, lady.”

Ken. I’ll bet.

Q. My little tractor is behind a line of big macho tractors waiting to get fixed. So I’ll be going home and push-mowing after I finish talking to you, Ken.

Ken. Eh!

Q. Push-mow a couple of acres, why don’t you?

the colors of our soils

Q. Before we talk to our next caller, let’s do one little quickie question, a funny one that came from Pam on Facebook:

“Can you tell if your soil is acid or alkaline by looking at it?” It’s an interesting question, and it had me thinking and thinking—and you know what I found out?

Ken. OK, I’ll bite.

Q. Did you know that the USDA website has information about a color system for soil? You can’t tell the pH necessarily, but there is something called the Munsell Color System, and what you can tell from it—like a whole paint-chip kind of a deal [laughter] with precise colors, this whole system that’s like a worldwide unifying thing about the colors of soil. And what it does tell is what minerals are in the soil, I think. It doesn’t tell you whether it’s acid or alkaline.

Ken. Are you kidding? Just by looking at your soil?

Q. I’m just saying there are indicators apparently about the mineral content, and a really precise system of looking at soil color. [Above, from the USDA page about the Munsell system, a chart of some of the color-mineral correlations.]

But I think that the only way to tell if your soil is acid or alkaline by looking—the only way you might know is if it was really that weird anaerobic-looking gray, if it has been swamped after a water event, which I would assume was acid. But I don’t think you can tell pH that way—I think Pam should get a soil test.

Ken. Yes, you can get a soil-test kit for a couple of dollars for a very general thing, but you can also tell by who’s growing there. If your lawn is doing very well, you are probably a little alkaline.  And if there is moss in some place, it’s probably a little acid. [How and why to do a soil test.]

Q. So “read your weeds,” as they say sometimes.

what comes next after removing invasives?

Q. We have a caller on the line, Lisa I believe? Where are you calling from?

Lisa. I live just outside of Lambertville, New Jersey, an hour north of Philadelphia.

Q. Ken, that’s sort of in your vicinity—not exactly, but…

Ken. I know where she is; she’s across the bridge from New Hope.

Q. And your question is?

Ellen. You were talking about nature abhorring a vacuum, and I have garlic mustard [above] a lot around here, and when I pull it, it just grows back. I was wondering what kinds of things  can I plant to take its place, and be more pleasing to the eye? I have naturalized purple-flowered Lamium, and the Brunnera with the little blue flowers like a false forget-me-not. Not much else grows and I don’t have time to run around and water the stuff when it gets dry. I need something that’s deer-resistant shade-resistant, and drought-resistant.

Ken. [Laughter.]

Q. Just so people have the backstory on this, what you are referring to when you say nature abhors a vacuum—well, loves a vacuum actually…

Ellen. [Laughter.]

Q. …or at least it takes advantage of a vacuum. Ken, on a recent show I was talking to Elizabeth Farnsworth of the New England Wild Flower Society, about invasives, and if you decide to remove invasives, like Lisa was just saying with the garlic mustard. What we talked about was that you can’t leave the soil bare for very long, because guess what happens? The stuff grows back, or something worse [laughter]. So that’s the context of the question.

I guess the answer is when people are removing invasives—whether garlic mustard or something else (and this answer of what to replace it with is region-specific)—is that when I weed it out I at least dump a bunch of mulch on top to shade the soil.

Ken. Yes, I was going to say that. What’s your mulch? The best mulch we like most is chopped oak leaves, if we can get them.

Q. And I use a composted stable bedding [above], like a very fine wood product that has been used in animal stables and has been composted—it’s dark brown and nice. But I definitely deprive that bare spot of light somehow, even if it’s putting cardboard on it [laughter] so it doesn’t pop up right away. But that’s not a permanent solution obviously.

Ken. But that’s a good thing to do, because when you pull those weeds, you’re disturbing the soil and bringing more new weed seeds up to the surface to germinate.

Q. As far as plants…

Ken. Lisa mentioned the Brunnera [above, photo by Ken], and I can’t believe it but I’ve got a whole patch of it in dry shade—in one of the hardiest spots I have. They flower and everything. You could do Ajuga in some places. Actually if you think about broad-leaf weeds [laughter] those would be great. Even violets if you have violets. Hellebores would be wonderful; they’re a little pricey but then they start to self-sow and you end up with a lot.

Margaret one of your favorite plants that you turned me on to a few years ago: Geranium macrorrhizum [below, at Margaret’s].

Q. Right. Do you know that plant, Lisa—the big-root geranium?

Lisa. I do, but I thought it needed a little more sun. The only place I have it is where it gets a little bit of sun.

Q. It can even do in shade and dry shade, oddly enough. But I was thinking of taking a cue from nature, so here we’ve removed the invasives and what if we added back some native species. I’d take the cue looking to see what grows in a natural area in my region that are deerproof. So for instance some of the native ferns. Obviously they grow in shade, deer don’t particularly like ferns.

Ken you mentioned the violets, and I find that rabbits and woodchucks like the violets.

The wood asters—there are a number of species that bloom in the fall and are great for adding more pollinator interest and fall interest to out-of-the-way garden areas. I love the white wood aster, which used to be called Aster divaricatus but they have renamed everything [Note: It’s now Eurybia divaricata] so I give up. [Laughter.

That’s the other thing to do is look on websites like GoBotany of the New England Wild Flower Society, or look in catalogs for the northern part of the country for regions that are not hot, dry regions, like Prairie Moon Nursery. They list possible underplanting kinds of things. That’s the other way to go—not garden plants, not horticultural aliens, but wood asters and ferns and as Ken said the violets, and lots more.

Ken. And Lisa is very close to a very good native plant garden—Bowman’s Hill Wildflower Preserve.

Lisa. I actually had some white wood asters that I got there one year, but I’m not certain what happened to them. Maybe it got too dry.

Ken. That’s a place to go and look—a living catalog of things you might grow.

Q. For people all around the country who have this issue—we’ve weeded, we’ve taken out our invasives, but we can’t leave a blank slate because we have disturbed the soil and brought up the weed seeds, as Ken said. Boom: we’re going to have more problems. So we either mulch immediately or shade the soil somehow—I mean, you could put a piece of burlap down if you can’t get to the planting right away, or cardboard.

But eventually the other place to look besides a garden center for horticultural plants is in a native-plant garden or a wild area around you. I was taking a walk today and there was baneberry, for instance [white flower below], in these types of difficult spots, and the native Asarum canadense, the wild ginger…


Ken. She can grow the native pachysandra, too.

Q. That’s a great plant—is it Pachysandra procumbens [below]?

Ken. Yes it is.

Q. That would be to me, no matter where people are living, a walk at a place like the one near you might provide inspiration and additional wildlife interest, pollinator interest.

Lisa. Can we talk about any eye-level things like shrub things?

Q. What’s above this—are we right under a tree?

Lisa: It’s kind of a fairly big area, and the far range of the view from the house. It was cedar trees that then have been succeeded by deciduous trees. There is some filtered shade, and it’s more dark shade where the cedars haven’t conked out and fallen over yet. By the middle of the summer it’s pretty dark shade.

Q. Ken, any thoughts?

Ken. [Laughter.]

Q. I’m adding more native viburnums, but they tend to want more light than that. I’m adding them along the edge of my property, but sort of at the brighter side of the woodland edge. For instance, the maple-leaf viburnum, Viburnum acerifolium, can take the most shade of the ones I am adding. Blueberries, the genus Vaccinium; I’m adding some of those. But you’re talking about an area that sounds a little bit darker than what I am working with.

Ken. And it sounded like you wanted some evergreen shrubs, or did you care?


Lisa. I’ve got this idea that I want to plant bottlebrush buckeye [in bloom at Margaret’s, above]. How much light does that need?

Q. I’ve seen it growing in bright woodlands and I have seen it growing in the open sun (as I grow it).

Ken. Yes, sun.

Q. A nursery near me plants it a lot for people in shadier places—and it will be looser and more open, not as heavy, dense kind of a big mound as in the sun. It’s hard for us not seeing the site exactly. Thanks for your call, because Elizabeth Farnsworth and I didn’t talk about “OK now what do you do?” we just talked about “pull them out.”

Ken. [Laughter.]

Lisa. Thanks a lot.

Ken. I’m still answering Lisa’s shrub question in my head; it’s a tough one.

growing bulbs like eucomis in pots

Q. How about a question on potted tender bulbs? I also want to talk about garden-tour prep a little, but Kathy on the blog comments asked something, because I have a story about Eucomis, the pineapple lily. I grow them in pots and stash them in the basement. I think you do, too?

Ken. Yes, exactly.

Q. She asks: “Can the bulbs be separated and located in new pots …or do you leave them as they are without dividing?” She says there are new babies, more bulbs in there than there used to be, with clusters coming up around them. What’s your protocol, Ken, for bulbs in pots?

Ken. Well, you can do either. [Laughter.] I let the medium in the pots dry in the fall. If they’re in a place where that won’t happen because of rain, I’ll turn the pots on their sides so the rain doesn’t go in. Then the foliage turns yellow, and I bring them into a cool, dry spot, and maybe during the winter I’ll sprinkle them with water a couple of times, in their pots, the Eucomis especially. And then in spring I decide if I like the three in one pot, or if 12 is too many for this pot.

So in springtime when they come out, still in their dry medium, I’ll dump the medium out kind of carefully because sometimes there is little new growth starting and you don’t want to knock that off like I did last week. You just sort of slide the medium out and rub it off the bulbs with your thumb and fingers, and then you can just repot them, and decide how many you want to put in a pot.

If I have some nice big ones I’ll put three in a pot together, and then have a little nursery pot, like kindergarten, with like 12 little ones and grow them on for the future.

I don’t know what’s happened with Eucomis, because I think I have like 12 different kinds—I have gone pineapple lily crazy.

Q. It’s so funny that you say that, because as many years and as well as we know each other, we haven’t talked about that, and me, too. I put mine in the basement and I don’t sprinkle them with water—there is no water in the basement and I’m too lazy, and I would have to carry it down a ladder like a firewoman or something [laughter].

But I have so many kinds, and there are so many in all the bulb catalogs. These are bulbs that we buy at this time of year, right, not in the fall, right? (Or am I going crazy?)

Ken. You buy them in spring, and you can also buy them in flower sometimes, or you can get them in the fall from some places. I got some at the Wave Hill plant sale in September, and they were past flowering but still had their foliage. You do the same procedure.

They’re hardy to Zone 7, so it’s not like a frost will kill them. They can probably go down to like 20 degrees even in a pot. But you do want to dry that soil, because if you put them in storage with wet soil they could rot, and you don’t want that.

Q. So depending how the pot looked, or if you have too many, or you don’t want the little babies—you can divide or you don’t have to. It’s sort of a visual and a performance decision; you use your judgment.

on opening the garden for visitors

Q. Our last subject, since we have both been through it: I just had Open Days, and more coming up, and wow, it’s a lot of prepping. [Laughter.] You have some stuff coming up, too. [One view of Ken’s garden, above; more at this link.]

Ken. I do, and I have resisted having tours—I always say, “Oh, there’s no parking,” and that helps me stop them. And then I started to have just a few people come for like a charity that would auction me off. And a bus can fit here sideways. [Laughter.] And then the floodgates opened, and now I have lots of tours coming. The good thing about tours is that it makes you get your garden in shape.

Q. It gives you a timeline, a deadline.

Ken. Dead is a good word. [Laughter.] We actually had a tree fall last week.

Q. Oh yeah, that’s good.

Ken. Just in time for all this. Usually when you are having a tour you spend $1000 at least, filling in some holes and making things look good. I keep saying to myself, “It doesn’t matter; they’ll like it.” But it matters, and I want them to like it—and I am not really even thinking about them.

It’s just like having a tour of your home. If you have a house tour, you really want it to look great and you end up doing some projects.

One thing I would suggest is to give a tour to some trusted friends, or even one friend, in advance, and ask the person to comment. Even if you are walking around with a friend and guiding the tour, you find yourself looking at things differently, and talking about things, and noticing the things that are great and that need some work.

The worst thing about the whole tour, and I know we were going to talk about this maybe, is what happens to the grass paths, oh my.

Q. Of course I had 2 inches of rain the day before, or 1.8 or whatever, and so guess what? All the little narrow places where you sort of walk from room to room in the garden, where the turf narrows: Those are all total mud at this point—dirt, compacted dirt. I have to do some turf repair at this point, and to me that’s the dreariest part of gardening: turf repair. I hate it.

And if you have another event coming up in a few weeks, you can’t do the kind of repair where you are nursing along these tiny little hair-thin baby pieces of grass for two months.

Ken. [Laughter.] Oh, I know.

Q. You said something about parking, and I have no parking, either. I’m on a dirt road and it’s a nightmare and was always chaotic. I’ll tell you the way I solved it: I bought a set of those highway cones. [Laughter.] What I did is I put them on one side the road meaning don’t park on that side, because it had been pandemonium with people parked on both sides and leaving like three feet in the middle only.

So I’ve found that I had to become a traffic cop—to think like a public institution. I guess what I am saying is if you’re going to have the tours, you need to have the gear. You’ve got to have folding tables—I ordered 8-foot folding tables for sign-in and so on. It is an investment, you’re right.

Ken. There is no way I could have a big Open Day for many reasons, and the main reason is that I am on an island between two one-land bridges, and it’s not very long between the bridges, so there’s no way anybody could park. It’s basically a one-lane road. You just can’t. So either I have a group coming, and I arrange to have all the cars come together—there is room for about four cars in my parking spot, which is like your driveway, and that’s it. Or a bus. But no chance for Open Days.

Q. But we like it, and we have fun. So in finishing up today in our “overtime,” just to say: Welcome people into your garden, whether it’s just a group of friends like your were saying, Ken—do a test tour—or a garden club, or Garden Conservancy Open Days that you can get involved with.

It really is a way to become a better gardener: Let people see it, and as you said, by giving even a pretend practice tour you learn what you really think about what’s working and not working in the garden. It makes you strive, don’t you think?

Ken. I do, and I think gardening is all about sharing, and a little bit of showbiz. [Laughter.] You want an audience reaction; we’re not gardening for ourselves.

Q. On that note: What did you say, “sharing and a little showbiz dot com”? [Laughter.] Thank you, Ken.

    • [Looking for the first segment (the first 24 minutes of the audio file)? Part 1’s transcript is at this other link, including how to work around wet spring soil without damaging it (or crushing desired self-sown seedlings), what to do about moles, or voles in the garden (and how to tell them apart), and more.]

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 seventh year in March 2016. 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 May 15, 2017 show right here. You can subscribe to all future editions on iTunes or Stitcher (and browse my archive of podcasts here).


  1. Misti says:

    I might be one of the few who got a kick out of the mention of the Munsell soil chart. It is something we use for wetland delineations all of the time. Definitely useful in looking at your soil!

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.