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mzstitch

How deep a hole for a polyantha?

mzstitch
9 years ago

On a whim today while at Roses Unlimited I purchased an Orange Morsdag polyantha. Most websites I visit state this rose will only be about 2 1/2 feet tall. I had thought it would be bigger so I'm now deciding what to do with it. If I decide to plant it in the ground how big a hole does it need? Because I have heavy red clay, when planting a regular size rose I dig 2 1/2 feet by 2 1/2 feet and amend the soil. But this plant won't be too large so I think I should be able to go smaller? If I decide to keep it as a potted rose what size pot do you think I would need? Yes, I should have asked these questions today but I had thought the plant would be bigger than what I now know it will be. I also didn't spend much time chatting there today as it was shipping day so they were quite busy!

Comments (11)

  • seil zone 6b MI
    9 years ago

    You might still want to dig and amend a good sized hole for it anyway. It will help it to settle in and grow better in the long run. Pretty choice!

  • dublinbay z6 (KS)
    9 years ago

    I used to plant roses in big holes like you mention (when I was younger and had more energy), but since I retired, I've been digging the holes more in the 1.5 x 1.5 range, and you know what? The roses seem to grow just as well! I dig the same size holes for most of the roses, including several polyanthas I planted a couple years ago--sometimes a somewhat bigger hole if the grafted rootstock is especially big.

    Kate

  • mzstitch
    Original Author
    9 years ago

    Kate & Seil, thanks for the quick reply. Knee surgery is in my future this summer, so I guess I was just hoping for the answer I wanted to hear! Okay, I'll go deep but not quite as deep as I usually do. This particular spot is the real dark red stuff the builder bought to surround the foundation so it really will be some hard digging. Thanks for the advice.

  • dublinbay z6 (KS)
    9 years ago

    Water the soil deeply the night before. The next day, it will be much easier to dig through that somewhat moist clay. (But be careful--if you overwater, you will have impossible, slimey clay--impossible to work with.)

    Or I have also, over the course of several days, lightly watered the first layer and dug, then watered the second layer down, digging the next morning, and finally watering the last layer down, digging the following morning.

    So much easier to dig if it is slightly moist.

    And I mix in a couple spadefuls of humus/compost--bag available at Home Depot for a couple dollars.

    Good luck.

    Kate

  • seil zone 6b MI
    9 years ago

    Excellent suggestion, Kate! I never thought of doing it in stages before. Not having to dig it all at once would really make it easier. Slow but sure wins the day!

  • mzstitch
    Original Author
    9 years ago

    Thanks Kate, yes I usually do make sure I water the previous day. This will be my first time digging deep in this dark red clay though that the builder bought in around the foundation. Likely got it really cheap, right?! I'm hoping it drains well so I don't waste time digging a hole I can't use! I've only dug the top few inches before for perrenials. Layers may just be the trick!

  • AquaEyes 7a NJ
    9 years ago

    I have clay soil here as well. Last year, I ordered a bunch of roses as bands (smaller than the 1-gal you got from RU), then potted them up when they arrived in April/May to grow a bit while I was preparing beds. Vigorous roses went into 2-gal containers, while smaller and/or wimpier roses went into 1-gal containers.

    By August, they were planted. And the holes I dug were just large enough to slip the rootball into the ground. Getting a hole large enough for a 2-gal pot was difficult enough in my clay, so any "amendments" I wanted in the hole were in the soil mix I used when repotting the bands -- equal parts peat moss, Bovung dehydrated manure, and shredded hardwood mulch, with a generous amount of granular organic rose fertilizer mixed into each pot.

    After they were planted, I put down a very thick layer (about 6") of composted shredded landscaping waste (the mulch sold by NJMulch.com), and in the Spring, lightly raked in composted manure, Milorganite, Ironite, Epsom salts and a pelleted organic fertilizer. In time, the rains and the critters in the soil worked to mix things around further, and the larger particles of the mulch filtered up to the surface while the smaller particles of the composted manure and fertilizers filtered down into the soil. At first, there was a little chlorosis among some of the roses (the clay here is more like chunky smashed red pottery subsoil than the nutrient-rich clay most people think of), but as the rains kept coming, fertilizer must have reached the roots and yellow leaves greened right up.

    So the moral is that if it's tough to dig a big enough hole in the soil to add amendments, you'll be OK adding amendments in layers on top. If you keep adding layers of mulch, manure and fertilizers every year, you'll have amended more than the just the planting hole -- you'll have better soil in the whole bed.

    :-)

    ~Christopher

  • michaelg
    9 years ago

    Clay soil is fine for roses, but clay fill that was compacted by the developer running heavy equipment over it is not fine for any gardening purpose. Your purpose should be to loosen the soil and avoid re-compacting it. Don't work or tread on the soil when it is wet. The best condition for working it is semi-dry, so that clods break rather than mash when you strike them.

    Deep holes with soil lighter than the surround will fill with water during winter or rainy seasons, and dry out faster during dry seasons. Therefore, modern horticultural advice is not to dig deep amended holes, but to prepare the whole planting area uniformly. It is fairly easy to break up the compacted soil with a mattock, letting the heavy tool do the work. Then dig in some manure, and don't worry about breaking up the clods into fine soil. A foot is deep enough--that's where most of the roots will stay anyway.. Then make holes deep enough for planting and backfill with the same dirt. Use 5 gallons of water to settle the soil after planting.

    As Christopher says, keeping the area under 2-3" of organic mulch will alter the soil gradually from the top. Putting coffee grounds or alfalfa under the mulch will soon attract earthworms to help modify the soil.

  • mzstitch
    Original Author
    9 years ago

    Thanks Michael and Christopher. I have put layers of cow manure on this area over the years and some perennials have been in there too so the top foot is likley not too bad its going deeper I'm worried about. I can't ammend the whole area right now, I have to limit my work as I have a bum knee I will have surgery on later this summer but I will try to do a wider area then originally planned. I will continue to amend from the top, great suggestions.

  • AquaEyes 7a NJ
    9 years ago

    Another way to gradually amend a large bed -- in Autumn, gather neighborhood leaves and shred them. Apply as a top-layer over existing mulch. In mid-Winter to early-Spring, scatter high-nitrogen organic fertilizer (blood meal, Milorganite, lawn fertilizer, whatever) over the shredded leaves. Don't worry about the fertilizer kick-starting your plants -- most organic granular fertilizers need to break down before they're available to the plants, and that doesn't happen until things warm up in Spring. But the extra nitrogen will speed up the breakdown of the Autumn leaves, and encourage earthworm activity which will further mix your soil.

    :-)

    ~Christopher

  • michaelg
    9 years ago

    You don't need to go deeper than a foot if the subsoil drains at all.