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etherealsunshine5

Will moldy straw (used in a burlap winter wrap) harm my roses?

etherealsunshine5
10 years ago

Anyone know if direct contact with moldy straw over the winter will infect my rose?

I have four bales of straw that the friendly farmer of our acreage dropped off late this summer. It rained on them before I got them covered...and now that I've cracked them open, they have gotten slightly moldy (white spotty spores).

While I wouldn't think of using them for bedding for my chickens, the other use was to be stuffing for the burlap wrap to protect a very large climbing rose...

I've read several posts that it's ok to use moldy straw/hay as mulch, but inside the burlap, all of the canes will be in contact with the straw all winter. I'm inclined to think that it will be fine and that the straw mold is more dangerous to me than the rose, especially when the rose will get a spray down with fungicide upon unwrapping in the spring.

This rose usually takes almost a whole bale of straw fluffed up to fill the wrap and it's late enough in the season that the only fresh straw I've been able to source locally lately is the super-compressed type which is a PITA to fluff up, not to mention a bit spendy.

Can anyone reassure me that my rose won't wake up with a cough in the spring?

Comments (7)

  • seil zone 6b MI
    10 years ago

    I suppose it depends on the strain of mold it is. If it's not black spot or powdery mildew it probably is fine.

  • blocke19
    10 years ago

    I use the old straw from our barn every winter and have never had a problem yet. It gets wet and moulds sometimes when used on roses or outside anyhow.
    I never use hay, if it 'mats' when i throw in down in the horses fields then it will surely do so in rose beds

  • lavender_lass
    10 years ago

    Um....I wouldn't, but it might depend on how much moisture you have in the air and how fast the mold will spread. It might be okay to cover old grass to start a new bed, but I wouldn't want it around (or on) the roses.

  • bart_2010
    10 years ago

    I agree with lavender_lass.I'd think that the presence of mould indicates the presence of bacteria, and I'd be concerned about that causing all kinds of rot problems,though maybe in your climate that isn't as much of an issue as it can be in my warmer climate. I am mounding my newly-planted bare-root roses, though I don't have to protect established roses at all. I am using wine corks and styrofoam held in place with sand to protect my babies; I like the styrofoam because it is light, does not absorb water, can be re-used AND is a way of re-cycling those hunks of styrofoam that is used as a packing material...bart

  • etherealsunshine5
    Original Author
    10 years ago

    Thanks for weighing in, everyone!

    seil--It's a white spotty mold...I think it's in the aspergillus family, which causes nasty respiratory infections, hence the no-go on poultry bedding/danger to me.

    blocke19--good to know someone else's roses have survived old straw. I'm not sure if I've really noticed mold when unwrapping in the spring--maybe just on the straw mounded directly on the soil. And I agree on avoiding slimy black spoiled hay molds--yuck! There's lots more organic material for bacteria to feed on in hay...Spoiled hay only goes into the compost pile!

    lavender_lass and bart_2010--I don't wrap until mid- to late- November when daily highs are near freezing, so I think that the cold should keep the mold in check over the winter. I'll be spraying it when it's unwrapped in the spring. This is for a Don Juan, which is not always cane hardy in zone 5 if we have a nasty winter. He's in a semi-sheltered spot, but he also hit about 12' tall this summer, so I'd like to save as much height as possible. I like your idea of reusing packing styrofoam...just not an option with this monster!

    Got my burlap yesterday, so now I'm just waiting for a break in the damp weather to wrap 'er up!

    Thanks again!

  • zack_lau z6 CT ARS Consulting Rosarian
    10 years ago

    Our winters are rather wet--I've had the best results just wrapping our roses with burlap in late November or December. I no longer have to worry about the filling material freezing into a solid block of unusable material since I no longer fill the burlap with anything. With more than 200 roses that survive every year, I've been paring down my winter tasks so I can grow more roses.

  • Campanula UK Z8
    10 years ago

    Yep, I definitely agree with Zac - I have protected tender palms and have simply used hessian or fleece on its own without any organic filling. Horticultural fleece alone raised the temperature by 3 degrees.