Growing hostas under trees - which trees work?

[ViolaAnn]

Hi folks,

I believe that the type of tree under which we grow our hostas, makes a difference in how well the hostas thrive or not.

Maples and especially silver maples or sm hybrids tend to have very shallow root systems and can provide significant competition for hostas (or anything else grown near them - my veggie garden is now full of tree roots).

I have a garden near my oak tree in which the hostas do very well. Oaks tend to have tap roots. I also have hostas growing successfully north of a large black ash and under lilacs.

But some of my other hostas are under or close to Linden trees - one in my yard and one just over the back fence in a neighbour's yard. I've noticed that the hostas close to the Lindens tend to grow more slowly and generally don't look as happy. The Lindens also have a tap root; so I'm at a loss as to why this happens. And I don't have a lot of space; so it's going to continue to happen.

But I wondered what your experiences are. Are there trees under which you have difficulty growing hostas? Can you guess why (competition for nutrients and water or does the tree have something in its composition that interferes with good hostas growth)?

And if you've had difficulty near trees, what (short of moving the hostas) have you successfully done to improve the health of the hostas?

Ann

[jerryshenk]

Well, we have a bunch of hosta growing under pine trees. I'm not sure what the root structure of a pine tree is like but I know there are quite a few roots rather close to the surface...makes planting them a pain. The hosta seem to be doing well but I can't really compare the growth there with growth elsewhere as I'm rather new to this whole game. They certainly aren't dying;) There was a big group of plain green hosta (Royal Standard perhaps) when we moved here. I've split them and re-arranged them and they seem to be flourishing. Other new additions (small plants) seem to be doing well. You would know more what's normal that I would...maybe some comparison pictures would help.

Sept 2011

DSC_20110902_122926 by jerryshenk, on Flickr

June 2013 (Royal Standard (?) on left, 3 DejaBlue (bottom one was planted in 2011), 1 June, 1 Abaqua Drinking Gourd, 1 June, the next grouping were large sections from a friend so that's not a fair comparison)

DSC_20130628_070106 by jerryshenk, on Flickr

We have also planted some under some holly trees - we only have a few there but they seem to be doing well but it's hard to compare the two areas - under the pines gets 4 hours of sun during the summer and most of the holly area is also shaded by chestnut trees and doesn't get any direct sun.

[redcrx]

I had a small holly bush tear up a couple of my hosta crowns. I took the holly out because there a bunch of other hosta in the area. I removed a bunch of hosta I had under a bigger holly that weren't doing very well and they were full of holly roots.

[Linda P]

I seriously wish I had been able to afford to build shade structures for my hostas, but with the huge numbers of plants I have, that would have required winning a lottery jackpot. So, I planted trees and large shrubs. A lot of them. Not always the best choices, because I was in a hurry to get some shade! I have one big maple in my yard and planted that strictly for fall color. No hostas live anywhere near it. I have an amur maple in a shady border, and I have root competition problems there. I have hostas planted under alder, ash, birch, chokecherry, dogwood, flowering crab, golden rain tree, heptacodium, hydrangea, lilac, magnolia, oak (pin oak and shingle oak), serviceberry, a very old row of spruce, at least 10 different kinds of viburnum, and willow. The worst are the amur maple, and some of the viburnums tend to sucker and have to be watched, along with the lilacs. The spruce windbreak where I grow my seedlings is at least 60-70 years old, and I plant in the area near the trunks. So far, very little problem with roots there, though some do creep in over time. I have 13-yera old hostas out there that are doing fine. That was probably the biggest surprise, that there is not more problem there. Oddly enough, I expected trouble from the willow but haven't had much problem.
A bigger issue for me is that I planted things too close together in my need to develop shade quickly, and now I'm having to prune constantly and remove some things to keep the shade from becoming too dense.

[kaylyred]

I grow under a red maple in my front yard, and another maple that I haven't identified in the back. Generally, I wouldn't recommend it, because maple trees have shallow root systems and can be pretty thuggish. BUT...under certain circumstances, and with a lot of determination, I've found it can work.

I have a few factors going for me here. First, I live near a river and the water table is high (as evidenced by how often my sump pump runs.) That innately high moisture level helps, because maples are thirsty suckers, but they're lazy and refuse to put down deeper roots looking for water. Second, my soil is light and silty, which means digging around roots isn't generally too difficult. Third, red maples are reported to be less aggressive than some others of the species.

I've found that if I keep my expectations in line (I don't expect my hostas to get as huge as some people's, and I don't expect to grow some of the more finicky varieties where there's root competition), and I water well when the weather's dry, I can grow hostas here under the maples. But it IS a challenge, and it's definitely not for everyone, or for every circumstance. Still, these don't look too unhappy, do they?

[jerryshenk]

The water table is an interesting piece to the puzzle - Our hosta garden is 10' or a little more above the level of the river which is 400' away. We definitely do not live in a dry area...in August when yards in local developments are brown, ours is still green. I think there are a lot of factors in this equation.

[Tigger]

We have a high water table as well (house is basically on top of a spring; the sump now feeds a pond), but red maple roots are an absolute menace in hosta beds, where we enrich the soil. Maybe they're looking for air and nutrients more than water. They have even successfully penetrated the SpinOut landscape fabric with which we lined our prize beds. Sigh. I'm starting a more aggressive plan of thinning the growth to create more "high shade," but have no choice but to leave some of the large red maples.

[Noreaster]

My largest hosta is at the base of a red maple. It's only been there for six years so I know there is still a chance the tree will get the best of it. But I try to stay optimistic.. I

I know we'd all like some sort of ideal situation- plenty of dapplesd shade yet no tree roots to contend with, but i think in most people's gardens, that's not realistic. The hostas will just have to deal. In addition to the red maple, mine are planted under birches, oaks, and pines.

[ogrefcf]

I built my own shade structures and I love it. No roots, not mess, and it's how I want it. I believe they grow the best out of all the hostas I have.

[Wheasie]

Under maples and conifers, I have them in pots and sunken. Roots will invade holes in bottom of pot, so I rotate frequently during the growing season - leave a good lip above ground so it is easier to grasp. I feed often with Osmocote. And when hosta roots have filled pot, I upsize the pot.