I´m new here - hello everyone! - and I was wondering if there are any known and working strategies to delay the growth of lilies?

That might sound like a stupid question, but I was thinking like this: where I do my gardening, in Mid Sweden, there is a serious problem with the lily beetle. The nasty bugger appears together with the first sprouting of the martagons in late March or beginning of April. The lily beetle then sticks to the martagons and leaves my bulbiferum untouched. I have often wondered why and then it suddenly occured to me: the reason why the bulbiferum is not attacked might be because there isn´t anything to attack yet. In my garden the bulbiferum is always the first lily to bloom, usually in the last week of June, but also the last one to show above ground. As I am writing this the bulbiferum are barely visible, the sprouts beeing just 1,5 cm small. So there´s absolutely no space there for the lily beetle to settle on and lay eggs.

So, my question now is: can I intentionally "delay" my martagons, making them sprout now, in the beginning of May, instead of one month earlier? I know this sounds naive, but I would like to try and see what happens - if the lily beetle emerges in the beginning of April and finds just an empty garden, with no lilies, it might wander on...?!

Greetings from Sweden where it´s snowing today

Chris! Thanks for joining us here. Sounds like a perfectly reasonable theory to me. If you could get lily emergence and lily beetle emergence out of synch maybe the rotters would die... I don't know if anyone has tried or studied it.

Longiflorum lilies and their hybrids are easy to hold back in cool store and plant at the desired time but I doubt it would succeed with martagons. Since martagons like to settle undisturbed in the garden for many years, I bet they would rapidly dwindle under a regime of annual lifting, storage and re-planting.

If I've been paying attention ( ), some of our North American gardeners delay garden lily emergence as long as possible to avoid late frosts, by mulching (insulating) the cold ground from the spring warmth. I have no experience there.

What about planting a crop of decoy LA hybrids every year, timed so that they emerge first, attract all the beetles and you could... ummm... incinerate the whole patch with a flame-thrower or something!

Serious problem and I have the lols... oh dear.

Hi Della,

Thanks for very useful feedback! "Out of synch" is exactly what I would like to achieve. The garden is very old, I bought it just a few years ago, and I suspect the martagons and the lily beetle have lived there forever in fatal co-existence. And now I have to disturb that unhappy relationsship.

Just two more questions. The martagons are already deeply rooted. If I were to add a thick layer of new soil on the martagons this fall, would that make a difference and perhaps delay them for 7-10 days?

But I think what I really should be looking for are "late starters", lilies who (like the bulbiferum) bide their time in the soil and won´t emerge until early May. Perhaps that would confuse amd irritate the lily beetle...
Which lilies are known to be "late"?

I´m afraid, neighbours won´t approve of me using the flame-thrower. It´s a very peaceful village in the middle of nowhere...

To delay martagon emergence in spring, delaying the rise in spring soil temperature would be the only way. But I would not add more soil on top. Your martagons have already stabilized at the soil depth they want to be at. Putting more soil above it would put them deeper than their preferred depth, and it might add to other problems. The safer and better way is to add a mulch layer. It will provide better insulating qualities without the detriments of planting too deep. Spread the mulch in mid to late winter, not fall or early winter. Let the cold penetrate the soil as deep as possible before you apply mulch. Your goal is to keep as much cold in the soil as possible. If you spread mulch in the fall, you insulation will also prevent the soil from getting very cold.

If you can provide spring shade in that area to prevent the sun from heating the soil, that would help immensely. But it cannot trap heat in, so you can't cover the mulch with black plastic, for instance. Your shade must be provided by something situated well above, to allow for adequate air flow beneath. (and of course, must allow water to pass through).

I don't have the lily beetle here yet, so I don't have any opinion, but I wonder if the beetles just like your martagons more than your bulbiferums. Your martagons being the first to emerge, of course they would be preferred, but if both martagons and bulbiferums emerge at the same time, what would happen? Does the in synch theory hold merit? Perhaps yes, perhaps no.

Leftwood, thanks for inspiring answer. That´s a very interesting strategy!

Of course I´ve always seen it the other way round; eager to protect the martagons from the first snow and icy nights I´ve applied a thick layer of mulch late in fall. But what you write really makes sense. I will definitely try locking the cold in. And a bonus from that method might be that this kills some of the beetles too. From what I know the last generation of beetles, born at the end of summer, work their way into the soil at the end of fall and then stay there for a nice long winter sleep. If they were to freeze to death in winter the problem would be solved – at least for next spring. (Until a new colony arrives…) So what I´ve been doing until now is sheltering them – keeping the beasts alive - in far too cosy temperatures. What a mistake, I realize that now…

Providing shade is more of a challenge. I live close to the coast and any passing storm would smash parasols etc. But until November I´ll come up with something.

Which lilies the beetles prefer seems to differ from region to region. Where I live the martagons are clearly top of the menu and the bulbiferums are left alone; strangely enough the close relative bulbiferum croceum seems to be under attack though. (That´s what people living close by tell me; I can´t really confirm since I don´t grow croceum myself.) Skimming through German garden blogs and magazines I see that Central European beetles do feed heavily on bulbiferum as well as candidum. So the only pattern I find in beetle behaviour is a high flexibility, a way of coping with local surroundings and adopting to what they find in each single garden…

That's interesting what you say about L. bulbiferum var. croceum. It is by far the most common in horticulture. Just last year, I received some bulbiferum bulbils from a friend here in America. I am very eager to cross it with L. maculatum.

Unfortunately, I don't think the colder soil in the winter would help freeze the beetle. We already have much colder winters in Wisconsin (USA) and Manitoba (Canada) where the lily beetle has established. But your climate is different (example: rainy in the winter) that might be advantageous.

Coastal winds and storms certainly pose their own problems. The shade structure would need to be substantial, like a low pergola made of wood and anchored to the ground. Shade could be provided by closely spaced wood lathing that would still allow rain to come through. Having that top removable after the sprouts emerge would be a plus.

You might also find that a mulch layer will just blow away with the winds. You may need to cover it with a netting or chicken wire or some kind of mesh.

Thanks again for good advice! Yeah, I was thinking in terms of building some kind of low pergola too. And with a netting as top it might be possible to weave in juniper branches or something similar to provide shade but also allow the rain to fall through.

Both L. bulbiferum and L. bulbiferum var. croceum are quite common over here. But the paradox is, neither can be bought from local bulb companies. Apparently there´s no "success guarantee" at all with these, more often than not they just vanish in the soil. I have loads of L. bulbiferum, but I strongly suspect the first ones growing here came from bulbils dropped by birds or spat out by some squirrels...

Chris @Semmering.

Sorry about the late reply. Lily beetles do seem to have a real appetite for Martagons. I guess all that lush early growth is hard to resist. LO hybrids and Lankon are also early favorites for them. Crown Imperials used to be my capture crop, but haven't worked as good since I planted Martagons... Could be a coincidence more than something else.

Unfortunately I think your strategy will have some obstacles to overcome, so might be less effective than you think. For starters, delaying the emergence of your Martagons would also delaying some of your lily beetles as you would mulch those as well. Also all lily beetles don't emerge at the same time. While lily beetles larvae need lilies to be able to grow to full size, the adults are also said to be able to feed on other plants. You also may have the problem with lily beetles flying in from neighbors if they grow lilies. This can be a significant problem right from the start of the season.

There is also the closely related species Lilioceris merdigera which looks very similar to the lily beetle and feeds on lilies too, but it has a more diverse appetite and that includes the larvae.

As for late to emerge lilies this certainly seems to differ between climates. However down here in Skåne, I noticed that many of the American bred hybrids are a bit later than the Dutch bred. No lily is later to emerge than 'Red Velvet' in my garden. It doesn't seem to be a favorite in spring for lily beetles, but they will feed on it later in the year.

Thanks William, much appreciated!

Yes, I can see the flaws in my strategy and I realise the beetles won´t be easily fooled...
However, right now they seem to be hiding. I think the cold weather has somewhat disturbed their life cycle. Two weeks ago I spotted and killed loads of them, all plainly visible on the martagon stems. This weekend I found only two, buried in the upper surface of the soil. And there are barely any new eggs. I´m sure the beetles bide their time and eventually will come back, but the lack of eggs might just be a sign that the much feared larvae production won´t be as grand as last summer...

Another newbie question!
Should I be worried about this:




The white-looking spots on the photo are in reality greywhite, kind of ash-coloured. As far as I recall the lily didn´t look like that last year. Not a disease, I hope...?!

Semmering said:Another newbie question!
Should I be worried about this:




The white-looking spots on the photo are in reality greywhite, kind of ash-coloured. As far as I recall the lily didn´t look like that last year. Not a disease, I hope...?!

I'm no mavin, but a newbie like you (that's why I'm here!). I have these on all my upcoming lilies too. I was concerned so I ran my fingers over the area trying to gently collect the little things. Mine ended up being bits of dirt that splashed up during a recent rain. I brushed them off and that was it. Gone. The ones I did this to are now about 6 inches tall, and look very good. The newer ones to nose up now have this on them too--it rained until yesterday afternoon so I'm not concerned.

Hope your's will turn out to be the same.

Bits of dirt! That´s a relief then. Thank you so much, Joanna! I was fearing the worst. But then again, the spots look kind of superficial and not like something coming from within the lily... I´ll go find a old toothbrush and see if I can brush them off

Glad to hear that yours are looking good!

Semmering said:Bits of dirt! That´s a relief then. Thank you so much, Joanna! I was fearing the worst. But then again, the spots look kind of superficial and not like something coming from within the lily... I´ll go find a old toothbrush and see if I can brush them off

Glad to hear that yours are looking good!

Thank you!

Be sure to use a soft toothbrush! If you really want to examine the bits to be sure they're not bugs, take a piece of scotch tape or packing tape and gently touch it to the side of your lily baby--firmly enough to get the spots but not so firmly that it sticks to your lily. Then fold it in half so that the bits are taped closed. Then take it to good light and use a magnifying glass or strong pair of reading glasses to see what it is. You can also take a picture using the close-up setting of your camera, even if it's just the phone camera. If they have legs, they're not dirt! If they don't, it's probably just specs of dirt and you're good to go! Here's hoping they don't!

The tape method sounds good, thanks! I really appreciate tricks like that. And I´ll ensure they don´t come with legs. But from what I have seen so far all the spots have different shapes, most of them look like ash flakes. If they really are bugs they certainly have a very relaxed dress code!

Be sure to use a soft toothbrush!

You might get away with an old soft toothbrush at this stage without damage, but in a week the new foliage will be even more delicate. I would use a paintbrush. The spots don't look like anything you should be concerned about. I wouldn't have given them a thought.

I think what really worries me, in an unconscious way, is the location of this particular lily. One year ago I tried to plant iris there, but they were always dug up by some nightly visitor; most likely a fox. Last fall I filled the gap with this lily and since then I hear this voice inside whispering that it was a very bad decision. Because everything growing there is doomed! The spots seemed to confirm that... But thanks for reminding me to use paintbrush instead. I´ll borrow one from my daughter...!

@Semmering, please let us know how it turns out.

I wouldn't even bother brushing off the dirt. The rain or wind will wash it away with no consequences.

Thanks Joanna, I certainly will! Right now work keeps me exiled from my garden, as I have things to do in another city, but the paintbrush action starts on Saturday. As I parted from home I surrounded that particular lily with twigs of last year´s thyme. They are dead but still very aromatic. A bit naive perhaps, but I thought the perfume would keep animals away

Joe, it´s just me being overcautious. Last year I failed to find a good location for that lily and then I replanted it in a pessimistic mood suspecting an endless chain of further problems...!