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laraine47

Any advice on tree root invasion

laraine47
13 years ago

I have a flower bed along a portion of our deck that is 6 ft 9 in. in length and 30 in. wide that is separated by a 3 ft wide interlock pathway with a wider garden on the other side that is home to an Ivory Silk Tree Lilac. The interlock path and gardens have been down now for 21 years along with the tree. I am having problems with the roots from the tree invading the flower bed on the other side of the path. I had to remove everything from the bed this June for a contractor who was demolishing our old cedar deck and replacing it with Ipe. When I dug up my hostas etc. which were not growing well I noticed the thick mat of tree roots and after I potted up my hostas I dug down 2 feet and filled one third of a leaf waste bag with tree roots. That is a lot of roots for such a small flower bed!I did the same process only 2 years ago and ammended the soil with compost and manure, but it seems that only helped the tree and not the hostas. Other than that, it is the perfect spot for my hostas as it is shaded by the tree and my question is....can I plant my hostas in plastic pots large enough for the hosta roots to expand but at the same time hopefully keeping out the tree roots? Or do I have to totally dig up the bed every year to get them out? I do not know how other people can successfully grow any hostas within the vicinity of a tree, and as far as trees go this one is considered small. HELP!!!!

Comments (14)

  • franknjim
    13 years ago
    last modified: 9 years ago

    I have two very large Silver Maples that have a million and one surface roots that occupy the top 16" of top soil. I started growing hostas here 10 years ago and many times have had to adjust where I plant a new hosta to fit between the larger roots. The thin roots from the tree do absorb a great deal of moisture and make it very difficult to plant or dig anything out. It takes me 10 times the normal amount of time to plant anything and must be done with a hand trowel, pruners and an axe. It is very frustrating to deal with but it hasn't kept my hostas from doing well. I sometimes come across a hosta that does not like the tree roots but not very often. I seem to have a problem with heucheras not liking it here.

    I don't bother to put anything in pots to bury as the roots are just a nuisance to me and not to my hostas.

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  • dbowemd
    13 years ago
    last modified: 9 years ago

    I have done pots in the ground and I have even done a double pot in the ground, so that the pot can be easily lifted out or spun to cut the tree roots... they do grow into the pots. It works well.
    There is a bag made for this too, which you can get from wildrose distributing. It is an inverted tree bag which stops tree roots from penetrating, which were initially made for puting trees in to be sold. They keep tree roots out with the same chemical treatment.

    Dave

  • laraine47
    Original Author
    13 years ago
    last modified: 9 years ago

    Thank you Dave for the timely advice. Using plastic pots was the only thing I could think of..I did not know of wildrose distributing and their root control bags. They are the perfect answer and are cheaper than buying large plastic pots for my stained glass hosta and fire and ice. Will also be able to use them for the hostas I have on the other side under the drip edge of the tree. They were huge once and are also getting smothered and decreasing in size each year. I expected that to happen there, but not on the other side of the interlock that was excavated quite deep down 21 years ago. The temperatures are in the 90's all this week, we are dying here in eastern Canada and it extends all the way to Washington DC. That is why I am on the computer and not out gardening.

  • keanaz5a
    13 years ago
    last modified: 9 years ago

    I have been using the bags from Wild Rose for 3 years now with great results. Here are some pics. All of these are growing in the root control bags under numerous maples.

    I have had maple roots get in the bag, so make sure and leave a lip about one inch above the soil level. And don't forget to turn the bag inside out.

  • randeld
    13 years ago
    last modified: 9 years ago

    I just bought some "spin-out" bags made by Texel (Tex-r Agroliner) from Acme-Mackenzie Nursery Supply. I e-mailed Matt Rocky (matt@mnsinc.cc) for pricing. I found the prices on their bags and the shipping very reasonable after some shopping around. I bought the 7 gallons (13" in diameter x 11 3/4" tall) and the 15 gallons (17" in diameter x 15 1/2" tall) bags. The 15 gallons bags are alitte tall so I cut 2"-3" off and turned down an inch or 2.

    This is my first experiance with the bags, so I'll see how they pan out.

    I too was having problems roots from a soft maple tree.

    Randy

  • ginny12
    13 years ago
    last modified: 9 years ago

    I grow hostas in the roots of mature maple and oak trees. My husband dug the holes with a pickaxe and I planted in pure compost. I topdress with compost occasionally and fertilize every spring with 5-10-10. I am careful about watering this bed on a regular basis because of the extra-dry conditions.

    This garden bed is about 20 years old and has done beautifully. Companion plants that have done well are variegated Japanese Solomon's seal, carex, epimediums, our native Geranium maculatum, and silveredge pachysandra.

    No doubt the plants would be even larger and lusher without the tree root competition but it looks great.

  • Steve Massachusetts
    12 years ago
    last modified: 9 years ago

    I have a good sized Norway Maple in front of my house that I don't want to cut down. It provides good shade on the south facing side of my house and it would take too long and be too expensive to replace it.
    Here's the maple in question. I took off some lower branches to allow for more sun.

    I decided to plant some Hostas beneath it in Spin Out bags. These fabric containers can be purchased from Wild Rose Distributing. Their advert is on the Hosta Library main page. When you get these bags you turn them inside out. The black side is supposed to prevent competing roots from invading the space of your plant. The size I bought was 12"x12" square and about 16" deep. Here's a bag in the hole. It's supposed to remain an inch above the soil surface.


    The planting area not only has root competition from the Maple, there previously was a Tree of Heaven (ailanthus altisima) in this area. This is an invasive, non-native devil plant that I have been digging out spraying with roundup for the last two years. Here's a pic of the root competition in the plant hole.

    I chose a mature hosta for this planting. It's a plant I haven't IDed yet. Last year it was scorched badly in the summer and I couldn't recognize it. But it's a huge plant. I had to divide it in half to fit it in the bag and it probably still has 30-40 eyes.
    Here it is planted in the bag.

    I added a bag of composted cow manure to the soil I used to fill the bag. You can see that when you fill it with soil the bag tends to assume a round shape more conducive to planting. This is a good spot for this Hosta as it will get morning sun, but protection from mid day and afternoon sun. I'm hopeful that the spin out bag will give it the root protection that it needs to thrive. I'll update it in the later spring when I can better identify the plant.

    Steve

  • beverlymnz4
    12 years ago
    last modified: 9 years ago

    Quite honestly, I have been reluctant to admit that I am growing hostas under maples. I worried that Hosta Welfare people would take them away from me and put them in foster care. I am ordering some bags ASAP.

    Does anyone have an idea what size bag would work for a large hosta like Royal Standard?

    Beverly

  • squirejohn zone4 VT
    12 years ago
    last modified: 9 years ago

    Steve,

    It will be interesting to see how your experiment with Spin Out Bags goes. I was thinking of trying them last year but didn't think they were large enough. The largest size advertised was 11 X 11 X 16" and Grenfell states"...hosta roots spread out below ground to the edge of the leaf mound or beyond..." and large hostas such as 'sieboldiana' can be 6-8' across and the planting hole should also be 6-8'. Since most hostas have a leaf spread of greater than 11" I assumed the Spin Out bags were too small and wound up cutting down a bunch of trees. I have another small area loaded with American beech roots that I might try Spin Out Bags based on your results.

  • Steve Massachusetts
    12 years ago
    last modified: 9 years ago

    John,

    That's a good point. Hosta root systems seem much wider than they are deep. You can see from the pic above that this division takes up most of this bag, and that was after I divided it in half. This is a medium to large sized hosta and based on what I saw last year it should be about 30 inches in diameter at full maturity. It may be that it outgrows this bag, but if that happens then I feel good about its chances of fighting off the maple roots on its own. I don't know about you, but I don't dig planting holes 6-8'! Next I will try a less mature hosta under this same tree.

    BTW, you can buy the spin out fabric on its own. Theoretically you could make a bag as large as you like.

    Steve

  • ken_adrian Adrian MI cold Z5
    12 years ago
    last modified: 9 years ago

    boy steve... wish you would have started your own thread ...

    anyway.. that nubbin you left on the maple ... how far does it project from the trunk .. looks a bit long to me...

    otherwise .. God's work ... keep it up

    ken

  • Steve Massachusetts
    12 years ago
    last modified: 9 years ago

    Thanks, Ken. That nub is about 2 inches long. Should I cut it closer to the trunk? I didn't want to get too close.

    As I think about this more, it occurs to me that I have a little more than a cubic foot to deal with, and I can make the bag fit the shape of the plant hole. So if I dig a hole 10 inches deep, I can get a planting hole more than 15 inches in diameter. I think I'll give that a shot next time.

    Steve

  • jyn510
    9 years ago
    last modified: 9 years ago

    I wrote what I did at:

    Tree roots in vegetable garden

    Diagram--

    This post was edited by jyn510 on Sun, May 11, 14 at 2:46