Sunday, March 17, 2013

Lots of Love in a Mist / Wild Geranium or Weed?

Love in a Mist? (Or weeds in a mulch?)

Near as I can tell, I have a bevy of Love in a Mist (Nigella damascena) seedlings springing up in my flower beds.

I sowed a small packet of Love in a Mist seeds last year, a few flowered eventually and now it looks like those fortunate few have replicated themselves en masse.

(Either that or I could be nurturing a crop of weeds with benign neglect, but from what I remember of last year's Love in a Mist plants - and from what I can find on the Internet this year - I'm pretty sure I have the right ID. Looking forward to their cheerful blue blooms and bizarre seed pods soon.)

Many Internet sources list Nigella damascena seeds as being edible (for instance Mother Earth Living and PFAF), although supposedly they are not as flavorful (and therefore not as frequently used for culinary purposes) as the seeds of N. sativa.

And speaking of is-this-a-weed-or-a-desirable-plant, does anyone want to chime in on whether this is really a wild geranium (and therefore presumably desirable) or a pernicious weed that I should pluck with all due haste?

Desirable wild geranium or sneaky weed?

Saturday, March 16, 2013

Eating My Words on Pine Straw

Mulching the grass -- the pine straw shown here has blown out of the beds over the past couple of months.  Of course, this is just the grass near one beds. A similar scene (or worse) can be seen around other beds. Sometimes I rake the pine straw back, but it just blows out again.

It seems like only yesterday (even though it was actually two months ago) when I said unequivocally, loudly and proudly that Pine Straw Makes the Best Mulch.

And now I will say three more words: "I Was Wrong."

(I will then qualify those three words to say, "I was wrong for me. Pine straw may still make a good mulch for some people in certain situations, but it's far, far from a good solution for every landscape."

So why have I changed my tune?

Weeds penetrating pine straw mulch with ease behind an HVAC unit.

I still believe pine straw has certain advantages. Let's look at the six claims I made earlier:

Pine straw is easier and faster to spread than other mulches - I still think this is mostly true. It is easier (since the straw is so light) and fast to spread bales of pine straw versus shoveling several cubic yards of mushroom compost (the only mulch I've tried spreading in bulk).

Pine straw is less expensive - Probably still true, at least initially (read on to see what I mean by that). A bale of pine straw does cover a lot more ground than a bag of mulch, so it probably costs less than bagged mulch even though a single bale is usually more expensive than a single bag of mulch. If you buy your mulch in bulk, I can't say whether or not it's less expensive than using pine straw.

Pine straw is more eco-friendly than bagged mulches - Still seems plausible, both because the pine straw is only packaged with twine (not plastic bags) and because you're not actually cutting anything down (as far as I know) to gather pine straw. Not sure of who wins the eco-friendliness contest between pine straw bales and unbagged mulch delivered in bulk.

Pine straw doesn't look all that great when it is incubating a bumper crop of weeds.

Pine straw looks better - Um, no. I don't think so anymore. Particularly after it has blown around a bit and has a lot of weeds growing through it (see below), I'd say I'm not that enamored with the look anymore.

Pine straw is easy to rearrange - Sort of, as long as you don't mind getting poked a lot by the needles. I will say that it is easy for the wind to rearrange the pine straw for you!

Pine straw stays in place when necessary - Ha! By which I mean, no, it didn't stay in place at all.

So now I will proceed to eat my words (a bit painful given that pine straw is so pokey) and tell you why my love affair with pine straw ultimately proved to be a torrid but fleeting romance.

A sprinkling of healthy weeds mixed in with pine straw around the base of a crape myrtle tree. Getting these weeds at the root won't be easy. You'll need to move aside the pine straw mulch first or simply grab, pull and lift a swatch of pine straw along with the weeds.

Pine straw did a fairly lousy job of blocking weeds - As I see it, there are three main reasons to use any mulch: (1) to beautify your landscape, (2) to improve the soil and (3) to block weeds. Of these three reasons, weed-blocking is probably the most important for me. And pine straw just doesn't cut the mustard in this category. Sure, in certain places if it's piled on really thickly it will suppress weeds (and swamp and low-lying perennials in the vicinity), but any places where you've only got a few inches of pine straw, plenty of weeds will be able to push through. And I'm not just talking about giant pokeweeds, proud dandelions or prickly thistles. Even delicate weeds will thread their way through the straw. Heck, even slender grass blades will find a way through. (And lest you think that the weeds are simply a function of me having not laid the pine straw all that well -- a significant possibility -- rest assured that the landscape beds installed earlier this year in the front lawn by professional landscapers are now also filled with grasses and other weeds. And this is only 1-3 months after the straw was laid down!! I shudder to think of the weed infestation that will be visible as the pine straw decomposes rapidly in the heat of the summer...)

Is this more pine straw that blew into the lawn? Nope, in this case you're looking at grass that has easily invaded the pine straw bed that my landscaper put down just a few months ago.

Picking weeds in pine straw is not fun - The pine straw does suppress some weeds, so what's the big deal if a few weeds get through. First of all, the pine straw will inevitably poke you when you try to pull the weeds, making an unpleasant task even more unpleasant. Second, if you try to pull the weed through the pine straw, you will pull up a decent swath of pine straw in the process and disrupt the thatching of the straw that supposedly (but not really) will hold the straw in place and keep it from blowing or washing away. So you have to first move the pine straw out of the way as best you can so that you can get a clear view of the soil and have a better chance of grasping the weed near the soil surface or digging down to get the root, remove the weed and then push the pine straw back into place, knowing that it won't be long before another weed sneaks through and you have to repeat the process. I'd estimate that the pine straw probably triples (at least) the time it takes to pull a given weed.

Pine straw flies like the wind - That's because pine straw flies with the wind. I was warned about this by a nursery worker last year, but I shrugged it off. Turns out he knew what he was talking about. We get some blustery weather down here. Very blustery. Like 20-30 mile per hour winds are not uncommon here, especially in the winter and spring. And this winter, we've had a couple of storms blow through with 40-60 mile per hour winds. Now I was concerned about this before buying the straw, but I decided to take a chance for two reasons: (1) our professional landscapers had used pine straw on the new beds and I figured they would be unlikely to use a mulch that had a tendency to easily blow away and (2) I had read online (and even seen photos) that pine straw could stay put in windy conditions and even in hurricanes!

I guess the lesson here is either (a) don't believe everything you read on the Internet or (b) at the least, Your Mileage May Vary (YMMV)

In any case, I did as the experts suggested and watered in the pine straw after scattering in to help it settle down and interlock, but subsequent winds still sent a good portion of the straw onto the driveway, into the lawn, piled up against shrubs that acted as windbreaks and goodness knows where else! Most likely some of my neighbors have pieces of my pine straw now!

I will say that not all the pine straw flew away in each wind storm. The pine straw that the pro landscapers had laid in the front lawn seemed to stay in place much better (not perfectly, but better), so it's clear that technique can make a difference here.

I think luck plays a role here too. If your pine straw has a chance to settle in for a few weeks and benefits from one or more good soaking rains that flatten and interlock the straw, it's probably far less likely to blow to the ends of the earth than if you scatter it, water it in and then have a wind storm (or succession of windy days) within the next week or two.

I also think location is a consideration. The straw seemed to be most prone to disappearing was the straw I had placed around the corners of the house where the wind would whip around the structure. (Our professional landscaper said that he had noticed this problem at other homes where folks had tried to use pine straw in foundation beds.)

So I'm prepared to believe that pine straw may be less prone to wind damage in some locations at some times, but I had lots of problems with it on my windy Tennessee hilltop, especially in the foundation beds.

Here's a daylily growing in pine straw mulch. Notice that the pine needles are sort of embedded throughout the foliage.

Pine straw acts like a magician with your perennials -- it makes them disappear! Months ago, when I told my landscaper I was thinking about using pine straw in my foundation beds, he warned me that the straw might be a bad idea because I had so many small perennials in the beds and the pine straw (being fluffy) could overwhelm and obscure the perennials.

In brief, he was right. With really low-lying perennials and groundcovers - things like ajuga, sweet woodruff, blue star creeper, veronica "Georgia Blue", creeping dianthus - you risk having the pine straw simply cover, hide and probably kill the small plants. (I say 'probably kill' because I kept going out there and moving the pine straw when it blew over the plants, so I didn't actually lose anything. But Georgia Blue veronica only get a couple of inches high. If the pine straw blew over it, I don't think it would go through the pine straw and I don't think it would get any light, so it would probably die.)

OK, admittedly you're not going to overlook this aquilegia plant, but it still doesn't look nice with the pine straw scattered over top of it. I didn't scatter the pine straw on this aquilegia - the wind did that for me.

With groundcovers that go dormant like hardy blue plumbago, the pine straw makes it very difficult to even see where your perennial was, so you risk stepping on it and/or digging in that area, thereby accidentally killing or damaging your plant.

With larger perennials or small shrubs, the pine straw won't kill the plant, but it will pile up against it, get tangled in the branches, and generally obscure the plant, making it look messy and less visible. In my experience, it's simply much harder to see most plants against the light-colored tangle of pine straw needles than against a darker and more uniform mulch.

More pine straw tangled up in more daylilies.

If not pine straw, then what?? So I had decided in despair that pine straw really wasn't working out for me after all. It wasn't blocking the weeds. It was blowing all over the place - leaving bare dirt in some places, piles of pine straw up against certain boxwoods and Indian Hawthorns and getting strewn throughout the yard. And it was hiding and diminishing the beauty of the perennials and shrubs.

I had to get rid of it - or at least not make the problem any worse.

But what could I use to replace it?

I thought (and still think) that groundcover plants would be ideal, but they're pretty costly (a single plant can cost anywhere from $2.50 to $10) and none of the groundcovers I've tried have filled in that quickly. And I was (and am) loathe to put in any super fast-growing but invasive groundcovers like ivy or vinca.

I'm still experimenting with groundcovers and have high hopes that some of them will turn out to be a good part of the long-term solution. As I've stated at least twice (this makes it three times), I'm really liking the sweet woodruff. Veronica "Georgia Blue" is tiny, but seemed to survive the winter with no problems. I like that it's evergreen and I like its little blue flowers. Hopefully it will flourish and I'll be able to divide it (or buy new plants). And I've got high hopes for experimenting with sedum and ornamental ginger, perennial geraniums and more.

But meanwhile, I've got to find something to cover the dirt and keep down the weeds that won't blow away, cover up the perennials and groundcovers, look awful or generally make a nuisance of itself.

Could pine bark nuggets save the day? Here are some mini pine bark nuggets that I used to cover a patch of ground where the pine needle mulch had blown away. I've included some neighboring pine straw mulch to allow you to compare color and texture side-by-side.

I went to Home Depot and looked at all the options and the one that looked best to me was pine bark nuggets - or more specifically, mini pine bark nuggets. Here's what I like about them so far:

1. I like the look. It's subjective, but I just like the nuggets. They're sort of rounded and make a nice pattern.

2. They're pretty light. Heavier than the pine straw and hopefully not so light that they'll blow away (they haven't moved noticeably yet on the couple breezy days we've had since I put them down), but probably only half as heavy as a bag of pine fines.

All the pine straw blew away from this bed at the corner of the house and driveway - repeatedly. So I put down mini pine bark nuggets. So far, I'm liking the look and they've been suppressing the weeds like a champ (for a couple of days). 

3. They seem chunky enough to keep down weeds. Pine straw is so fine that there are lots of places for light and weeds to keep through. Larger pieces of pine bark nugget seem broad enough to hopefully block the weeds in most places.

4. They give perennials their place in the sun (or shade). They don't swamp or cover up the perennials. Even tiny perennials like the Veronica "Georgia Blue" or the nearly-flat creeping dianthus can stand up and stand out against the pine bark nuggets.

Even tiny perennials like Veronica "Georgia Blue" that would get swamped by pine straw stand out against the mini pine nuggets.

5. They're durable. Pine bark nuggets decompose slowly. Various sources say they can last approximately three years. (The bigger nuggets seem to last almost indefinitely, which seems to peeve some gardeners who want their mulches to decompose and feed the soil, but the mini nuggets apparently have sort of a three-year lifespan.) That's in contrast with fast-decaying pine straw mulch that supposedly has to be refreshed once or even twice a year - and that's if it doesn't blow away! ;-)

I believe this is a wild geranium. (It may just be a weed.) Either way, it's standing out nicely now against some newly spread pine bark nuggets.

6. No chiggers? Janet QueenofSeaford commented on my last post by noting that she dislikes pine straw due to the fact it often contains chiggers. Also some folks have commented about snakes living in pine straw. Or voles hiding under it. (Perhaps the snakes enter the pine straw to hunt the voles?) Either way, I'm hopeful that the pine bark nuggets will harbor fewer pests. (Not that I have anything against snakes, voles or chiggers, I'd just prefer not to have any of them in my landscaped beds!) Of course, the one benefit to pine straw from a pest perspective is that it is supposedly unattractive to termites, but I was planning to purchase trap-based termite control protection this year anyway.

The pine straw blew away from these daylilies on its own. So I surrounded them with mini pine bark nuggets.  There are still some pine needles trapped in the daylily foliage, but I can pick those out at my leisure.

7. Less fire risk. Some folks around here, like the guy who takes care of our sprinkler system, warned me about the flammability of pine straw as a mulch. From two studies that I could find online (University of Nevada and Journal of Arboriculture) it does seem that pine straw is more dangerous than pine bark nuggets from a fire perspective - particularly with regard to how fast flames can spread through pine straw. Interestingly, both studies note that rubber mulch is very dangerous from a fire perspective - that it catches fire easily, burns very hot with high flames and can be difficult to extinguish. I didn't know that and wouldn't buy rubber mulch anyway (doesn't feed the soil and who knows the source of that recycled rubber?) but I wonder if the folks buying rubber mulch know of its fire hazard issues? (Here's a post from GardenWeb talking about pine straw mulch being implicated in some devastating fires in North Carolina. This is apparently an especially big issue if you live in a home with vinyl siding.)

8. Less messy to spread. Wait, didn't I say that spreading pine mulch was easier than spreading say mushroom compost? Yes, but that doesn't mean it's always fun. Your mileage will definitely vary here because pine straw is not a standardized product. The quality of the straw depends on each supplier. I purchased pine straw three different times from three different suppliers and the quality was variable each time. The first batch of pine straw (from a nursery) was the best. (It was also the most expensive at more than $6 per bale!) Clean bales of good-quality and long leaf straw. I think I had maybe a few charming pine cones from all six bales, but the rest was just straw. Sadly, the next batch of bales (from a landscaping company, ~$4 per bale) were the complete opposite, filled sticks, dirt and debris. It was dusty and messy to spread. I actually wore a mask over my mouth so I wouldn't have to breathe in all the dust. And the pine needles themselves were broken and shorter than the ones in the previous batch. Frankly, if the first batch of pine straw had been as bad as the second batch, I would never have kept trying to spread pine straw mulch or written my initial ode. The third batch (from Home Depot, ~$4 per bale) was of intermediate quality. Less dirt and debris, but the needles weren't as beautiful or long as those in the first batch.

9. Much less messy to transport. Yes, I feel guilty from an ecological perspective about buying bagged mulches, but I will say that pine straw bales tend to shed their needles in the car on the trip home. Certainly not the determining factor here, but unless you have a pickup truck and can hose out the bed after the trip, you'll probably want to bring a tarp to put in the car before loading up the pine straw. And even then, count on picking out and/or vacuuming out pine needles afterwards.

Callirhoe bushii (Bush's Poppy Ballow) was practically invisible in the pine straw. It pops nicely against the pine bark nuggets and seems in no danger of getting buried.

Conclusion - So far I'm loving the pine bark nuggets. But I said that two months ago about the pine straw. So time will tell. The one thing I'm a little worried about is that we don't just get high winds here, we also get heavy rains fairly regularly and some sources warn that pine bark nuggets may have a tendency to float or wash out of beds that are not edged. (Ours are not edged.)

So we'll see about that. At least I am only using the pine bark nuggets on a flat ground, so that will hopefully reduce the risk of them washing away, but I have a feeling that there will probably be some mulch erosion from at least one particular corner near the house and driveway.

As for pine straw, I can see it having limited utility in certain specific circumstances. Wind may wreak havoc with the straw, but rain doesn't seem to faze it, so I can see it working on a hillside (as where my landscaper used it) where other mulches might wash away. (Although I should mention another hazard here that some folks mentioned to me and I've experienced myself -- pine straw gets very slippery when wet. Used on a hillside, it becomes even more hazardous. So if you do spread pine straw mulch on a hillside, I'd avoid it (or at least be very careful walking on it) after a rain.

I could see pine straw also being a decent solution in a very calm environment where there were either no high winds or where there were lots of trees and shrubs to block the wind and create a sheltered microclimate.

And I could see it working over a large area planted only with trees and large shrubs where there would be no concerns about perennials and smaller shrubs getting lost in the mulch.

But even in those areas, it seems like weeds will creep through unless you either (a) lay a very deep and thick layer of pine straw (at which point I'd be worried about critters in the straw, fungus and water getting to the soil) or (b) use weed killer. I think my landscaper is planning on using Roundup (i.e. glyphosate) to take care of the grasses and other weeds growing in the new landscape beds, but I think you'd have to be careful not to kill any valuable plants in the pine straw and besides I hate spraying herbicides or working where they've been sprayed so that's not a good solution for me.

Bringing this opus to an end, I'd like to repudiate my previous praise for pine straw. To anyone who was swayed by my earlier post to consider pine straw for their own landscape, I apologize.

Now stay tuned for an update in a couple of months as to whether my current fling with pine bark nuggets will develop into a stable long-term relationship! :)

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Friday, March 15, 2013

To Prune or Not To Prune ... Sweet Woodruff

Sweet Woodruff in March 2013 - battered but unbowed
UPDATE - As time goes by and I see how a plant performs in the garden from year to year, my views may change and I'll update old posts accordingly. That's what happened with sweet woodruff. I started experiencing dieback on patches of this plant in both winter and summer. I suspect it's a bit difficult to grow in the hot and humid Southeast and especially the Deep South. At the same time, when I started to try to dig up patches, I found a disturbingly elaborate web of roots that seemed to occupy the entire top layer of soil. I could literally lift the plant and the soil would come with it like a piece of carpet. So I ended up evicting sweet woodruff entirely from my garden. Fortunately, unlike Ajuga or Geranium sanguineum at least it had the decency to leave politely and not try to make too many repeated comebacks. I've since shifted my gardening more toward natives, especially vis-a-vis spreading groundcovers. If you do grow this plant in the U.S., please check to make sure it's not invasive in your region, as might be the case particularly in the Pacific Northwest, Upper Midwest and parts of New York State.

So far, I'm still loving Sweet Woodruff (a.k.a. Galium odoratum). Not loving it anymore. Shovel-pruned it.

I first planted some last spring, it survived our scorching summer last year, so I split off some last fall, and both the division and a new plant that I purchased from a nursery last autumn have done well and seem to be growing and expanding.

(That's opposed to other 'groundcovers' I've purchased that have either (a) died or (b) covered very little ground so far.)

So that's why I sang Sweet Woodruff's praises a couple of months ago. At the time, the plants were welcome shades of green in an otherwise relatively brown and bare landscape.

Well, I'm still enamored with the plants, but they weren't quite as evergreen as I'd hoped, at least not in our average zone 7 winter. Our coldest temps were in the high teens this winter, but most nights were in the 20s or 30s.

Anyways, my question is this -- For anyone who grows or has grown Sweet Woodruff, do you prune off the old tattered foliage or if you don't do anything will the plant shed the old foliage on its own as the year progresses.

Lots of healthy new Sweet Woodruff foliage emerging from underneath the messy mop of foliage pictured above. Should I trim away the old growth or will it fall away on its own (and how long would that take?) as this new foliage takes center stage?

I only have the three small Sweet Woodruff patches right now (actually one small patch, two tiny patches), so I certainly wouldn't mind clipping off the old growth this year, but I have two concerns:

1) Perhaps the old growth is there to shelter and protect the new growth as it emerges? After all, no one's pruning Sweet Woodruff in the wild.

2) Alternatively, if the old foliage will persist throughout the year and it's better to give it a haircut to let the new foliage have its place in the (partial) sun, that's good to know before I let Sweet Woodruff run rampant and find myself faced with the task down the road of pruning an acre of last year's Sweet Woodruff foliage on my hands and knees.

Ergo, I welcome your opinions, suggestions and personal experiences on this edition of To Prune or Not To Prune! Thanks :)