Why are some of my hosta getting smaller?

[loyal & true]

I have read this board for a few years but have only posted one time. While wandering around my yard with a glass of wine in hand I have noticed that three of my hosta are much smaller than in years past. They are June, Ryan's Big One and one I think is Blue Boy. What would be causing this and is there anything I can do to make them grow again? We had the coldest, snowiest winter that I can ever remember, but only those three seem to be smaller. Thank you for any suggestions you might have.

[Chris_W]

Hello,

The main cause tends to be lack of moisture from the previous season (are these three in dry spots in the yard?) and one of the biggest culprits are roots from trees and shrubs stealing the moisture before the hostas can get a drink. If you had a very dry summer last year compared to others it might have just been a one time problem but you might dig in the vicinity of these plants to see if roots are invading. If so you might consider reworking the spots or moving them.

The other possibility is damage from mice/voles which can eat hostas over the winter, but in this case the damage is usually dramatic.

If the crowns are showing at the surface this could also be an issue as they will dry out quicker than if they were buried.

I would check for tree root issues myself.

Good luck!

Chris

[jgh]

I had the root problem... a silver maple that started out really little and grew really big... and I liked the increasing shade... but year by year really nice big hostas got smaller and smaller... it was a creeping problem, occuring while my attention was on expanding in other areas. I took down the tree and they are slowly recovering, but I really learned about how even well established hostas can slowly be strangled by tree roots.

[kHT]

How about pine needles that smother them? I water like crazy in this area due to I know it's dry so watering isn't a problem, I just have tons of needles dropping.
Chris or other hosta growers, need some input here.

[Noreaster]

Ugh, you guys are scaring me. I've got a lot of tree root competition. There is nothing to be done for it, since I can't cut all the trees down, or expect the neighbors to cut down theirs. I'm confused, though. I've seen many pictures of lush hosta gardens amidst the trees...how is that possible if tree roots are such an issue? I don't think too many people have hosta gardens in the middle of barren fields, right?

[Ginger]

I agree, tree roots or critters. Where in OK are you located? (don't have to be specific, just general area) Do you have clay or sand? I live about 27 miles east of OKC and my soil is very very sandy, but I grow my hosta in pots becaue of the critters and the constantly changing weather.

Good luck, hope you find the cause!

Ginger

[jgh]

The tree root issue is much discussed... do a little searching and you'll find lots of solutions listed.

To answer your question about hosta gardens under trees... all trees are not created equal. Some rely on deep tap roots and hostas can grow right up to the trunks without too much competition as long as moisture is constant. Others, like the maples, tend to have networks of small, shallow roots that fight with the hostas for water and nutriets.

The silver maple I mentions is an extremely fast growing maple - and it does it by developing a huge network of tiny, wiry roots that rob every bit of moisture and nutrient they can from everything else around. When I tried moving hostas in the active growing zone of this tree, I had a terrible time chopping all the way around the plant, cutting through hundreds of roots in the top few inches of soil. The roots grew right through the hosta root ball - in fact, I found silver maple roots growing through crowns and piercing the hosta roots and growing right through them!

You can check the root issue pretty easily... dig near your shrinking hostas and see if there are tree roots competing. If it is just a few, you can make up for the competition with some extra moisture and maybe some feeding.

Solutions other than cutting down offending trees... Some people grow above ground in containers. Some sink large nursery containers to just below soil level and then take measures to minimize the invasion of roots into the pots. A newer hi-tech approach involves growing in sacks impregnated with - I think it is copper??? - that turn the roots away.

[Noreaster]

Yes, I'm aware that maples are notoriously bad to grow under, and some maples more than others. That new high tech sack thing sounds interesting. Still, just google images of hosta gardens and you'll find many- most, even, have trees in the immediate vicinity. I have a hard time believing that most people would go to the effort to bury every hosta in a pot. Many of mine are too big now to dig up and pot up, even if I wanted to. I guess I'll just have to keep my fingers crossed that they will not dwindle down as the years go on. So far they are increasing well. My garden was started in 06 and the majority of my trees are oaks and pines.

[Chris_W]

Hi,

Oaks don't have a problem, and pines aren't usually too bad either so long as you can water the hostas well. When we talk about tree roots, like JGH mentions, some roots go deep, others are big and branching but generally easy to plant around, but the worst are those that are shallow and fine.

I have walnut and oaks and no root problems at all. I can even rototill right up to the base of the trees and don't hit any roots (not even large ones).

Pine needles shouldn't hurt hostas, even if there is a couple inches covering them. It would be similar to mulching the bed and the hostas should be able to adjust to the depth provided they mostly get covered while dormant.

[fullofit]

I did a raised bed, under a maple tree (this was at least 6 years ago). I used copper impregnated cloth that I purchased on line from a nursery. I overlapped the cloth and it went up the sides of the raised bed. Then I filled the bed with mineral enriched sifted topsoil. I now notice that in the last 3-4 years, the roots have found their way through the cloth and are infiltrating my soil. Nothing is suffering yet, but I'll keep my eye on it. I'm not too happy that the solution may be to remove all the soil (20 yards), and replace the copper cloth, and replant. I may be too old to tackle a task like that.

[loyal & true]

Thank you so much for your help. Two of my hostas are in beds with Japanese maples which have really taken off in the past couple years. I dug the hosta up and there were many fine roots around the hosta so that definitely could be the problem. My whole yard is full of oaks and they have deep tap roots and have never been an issue, but over time the new Japanese maples, huge hydraganeas, and acuba might be competing for moisture, nutrients and space. They are going to have to learn to get along with each other because I really love them all!
Chris, I don't have voles, but do have plenty of MOLES---argghh. I don't know if they like hosta (I think grubs are their favorite snacks), but they are driving me mad.
Ginger, I live in far west Oklahoma City and also have sandy soil. I think the only reason my hosta do so well is because I am in pure shade and am protected by trees and a hill. After I read how you use pots, I planted Krossa Regal and Green Milk in large pots two years ago and they are doing great. I guess I'll use pots in the areas near the Japanese maples.
Great advice everyone!

[Kas]

Karma, do you have any spruce, cedar, or fir growing anywhere near those pines? I have the same problem in some areas. I think cedar is the worst for me and then the Doug fir. I had to remove a very pretty hosta bed from under the cedars since they were all shrinking away. Same thing with the fir. And the little needles from the fir clog the petioles and I think keep the water from getting down to the hostas. Good luck on that one!

Kas

[renaldo75]

I had major root problems with an old old established flowering crab tree. The roots are just as bad as the silver maple roots I think. My original hosta bed was under the crab and over the years I moved almost every hosta that was under it. The roots would grow right into the root mass under the crown and stay there. Sagae, Collector's Banner, and Tokudama Flavocircinalis were the only hostas that didn't seem to be effected much by the roots, but I'm sure they'd have been much larger by now if they'd been somewhere else.I had a heckuva time getting those roots out of there. Even ones I moved quickly out of the way of a new water line a couple of years ago. When I redug them to pot last year, I found the crab apple roots still alive and well in the root mass. I thought that was pretty bizarre.

And I am one of the crazy ones. When I moved my garden to its new location for the tour this year, I planted everything in pots. Several reasons: I didn't want to change the look of the 'land' where I was moving them too; the soil here is not good in several places; hauling in more soil/compost would have been very expensive; lots of tree roots here too, but not the same kind; and if/when the hostas move back to Corning, they'll have to deal with tree roots again. So I got the copper coated cloth, cut it into small squares and duct-taped them to all of the pots I planted in. I would not advise it unless you have a ****load of time to kill well in advance of digging and potting your hostas. It took me at least an hour to do a dozen pots no matter the size of the pot. And I did a lot of big ones and a lot of small ones. Set back the speed that I was able to move the garden. But I didn't have the majority of the pots until late July. And I was doing it for about 700 hostas. As I said, I'm one of the crazy ones.

[Noreaster]

Where do you even get pots big enough for the larger hosta to grow to maturity in? When you say "pots" are you talking about the thin plastic nursery pots or something else?

[kaylyred]

My hostas seem to be okay under my red maple. I do encounter a few roots when I'm digging but not of the oh-my-gawd variety I hear some people talk about when they refer to digging around maples, so I can only guess that the red maples might not be among the worst offenders when it comes to root competition. Still, my plan is to plant my more common hostas under the red maples and save the more special ones (well, they're all special, but you know what I mean ) for other beds where they won't have roots to fight with.

[Noreaster]

Kayly, I have some hosta under a red maple too, that seem to do ok...thriving, really. But now I'm in a panic that it's just a matter of time before they are choked out by the maple roots. BUT, I have read somewhere that red maples aren't bad, like the Norway maples, etc. So I don't know. I'm thinking about digging a few of the better ones up and putting them in those root blocking bags while I still can...but really don't look forward to that! If I don't get to it, I'm going to try to just think positive. Hopefully the maple will die before any of the hosta do.

The other day I did dig up June which was by a birch, and there were tons of tree roots with that. Still, June looks huge and lush this year despite the competition?

[Ginger]

Noreaster, I get my pots from Home Depot or Lowes. I use plastic and I will have some problems finding bigger ones in the near future, although I have noticed they are carrying bigger pots this year than I have seen in the past. I don't use the growers pots because they are not sturdy enough to withstand moving them around alot, and DH and the weedeater , plus the black just sucks up the heat and keeps the soil to hot. Hosta in the south will not get anywhere near as big as they do in your area so that helps

Ginger

[renaldo75]

Noreaster - the pots I used for the most part were all 'growers' pots. As the size gets larger, they are much more substantial than the one and 2 gallon pots you're thinking about.
At least the ones I was able to find from Steve & Deb's basement [can't think of their name on here at the moment] over in eastern Iowa, and Trudy, and one other friend were all 3-7-10 gallon pots and were pretty durable. For 3 of the largest hostas, I used 15 gallon ones that are actually for feeding livestock out of. I drilled holes in them for drainage.

[jgh]

a guy came to my sale last year who knew the folks at a local tree service/landscaping place. He vouched for me and they let me choose from a huge pile of stuff that was going to go off to the landfill... maybe 300-400 gallon pots and a nice assortment of those heavier larger pots. They were glad to see them go - saved them loading them up.

Note - if you find a source like this, check the pots out as you load them. I ended up with stacks of gallon pots that had been split down the sides. The guys on the crews planting these obviously weren't spending a lot of time carefully removing the perennials from the pots... they just sliced down the side of the cheap gallon pot with the blade of the shovel and popped the plant out. I got lots of good ones, too, but had a bunch to send out in my garbage. Wished I could recycle them, but our city has restricted plastic recycling...

[Noreaster]

I've inquired at a few nurseries this week if I could buy some of their larger nursery pots, but they seem quite expensive. A few years ago I stopped at a place that carries a lot of trees and they gave me a nice big pot and said to come back any time, so I will probably head there this week. I don't mind the flimsy nursery pots if they are just going to be buried or slipped into a more decorative container. One issue is that many of the bigger pots are also really tall, and those can't be as easily buried, because you don't have to dig far here to hit solid rock. I know it's not ideal, but I'm sure most of my plants' roots grow more out than down because I just can't provide a ton of depth.

If it's true a hosta's root spread extends to the edge of it's leaves, realistically, how big a pot would you need for say, "Guardian Angel"?