I’m a new hybridizer and the Colorado weather has made the task VERY challenging since I grow roses surrounding my condo and have no greenhouse access. Today in Denver it’s 90 degrees. Tomorrow it will be 25 and snowing…the earliest frost date in recorded history in Boulder, CO! I have about 17 immature hips in my garden from pollinating on June 15th and I’m not sure if I should try to insulate them from the frost while leaving them on the bush or just harvest now. What do I do? Even covering some of my smaller roses with buckets and blankets and adding “Hot Hands” heating packs under them may not prevent the hips from freezing. Can I simply cut the canes with the hips on them and mature them indoors (in a sunny spot) in a cup of water for the next month? Or do i snip only the hips and let them dry/mature inside without water. I’m so frustrated that the weather will likely be sunny and 80 degrees again next weekend and for weeks thereafter, but I have to act now if I want to have any 2021 seedlings. HELP!
Thanks in advance,
I’m soo sorry. How large are the rose plants? I’m glad there are about 3 months maturation to this point. I’d be torn between covering really well and cutting the hips like cut flowers with leaves and using floral presevervative to mature them a bit longer. What a huge temperature difference…
Typically light frosts aren’t too bad on rose hips for seeds that are well along, but that is after a gentle transition. Hopefully really good insulation can hopefully buffer things. If it was just a few plants I’d be tempted to wrap them up really good with old comforters/blankets from the house and use stakes, etc. for support and plastic or a tarp around/over it all with bricks to hold it down on the edges. The heat from the ground will hopefully rise up enough under there to keep things a few to several degrees warmer and the plastic/tarp will keep the insulating material dry to keep the r value up. Hopefully the cold won’t be around too long…
Are the hips starting to show some color yet?
Wishing you the best to get through this cold snap safely.
Thanks so much for your feedback! A couple of plants are small enough to be covered up with buckets if pruned slightly, but most are huge. (I also have three still-small seedlings that I’ll be insulating REALLY well in order not to lose them in this storm.) I thought about running a hips experiment: leaving the hips on the smaller plants, but covered them, and just harvesting the hips on the larger plants, hoping they will mature indoors. Unfortunately none of the hips are really showing any color change yet. Last summer I didn’t get around to pollinating until July and the freezing temps came in early Oct, so I thought this year I’d be better off. Oh well! Thanks again!
I have had success harvesting them early by taking the branch exactly as I would to root a cutting, some have even rooted while I was waiting on the hip to ripen. I also, as David suggested, kept the cutting in water and gained a couple weeks. I cut it regularly and gave it fresh water. Maybe you could get enough time with one of these methods for the hips to ripen. I don’t know if the length of cutting would make a difference or not.
I wound up harvesting about half and covering the others (entire plants) using tarps, buckets and blankets. My guess is that the 6" of snow will also help to insulate! Hopefully with this combination I’ll wind up with a few mature seeds in the end. Thanks so much for your detailed info about caring for the hips-on-canes. I’ll do as you suggest, keeping them in fresh water and keeping my fingers crossed. Thank you again! -Sue
Let us know how things turn out, I hope both work for you!
Out here on the plains (eastern KS) we often have transient frosts. For radiative cooling when clouds disappear overnight, even a single bedsheet or large drop cloth of plastic will protect peppers or tomatoes if the ground was previously warm. Snow, as such, does little or no harm on roses. If you have daytime temps that don’t rise above freezing, that’s another matter. I saw zoom photos from Denver yesterday afternoon and all the snow had already melted because the below freezing time if any, was very transient.
I have successfully taken cuttings of hips 6-8 inches and kept them under lights for many weeks until the hips ripened, potted in soil and covered with a plastic veg bag from a grocery. Seeds from those hips germinated, though at a lower rate than those matured on the plant and harvested a couple months earlier. They were taken much later in the season when a guaranteed hard freeze was imminent. It’s pretty well documented that cold weather near harvest decreases levels of easy germination, and maybe total germination. This was true in Pacific NW and in Europe, so you’ll expect less good results with cold weather than if it had stayed warm right through until Oct.
Good luck with your seed crop.
This is great advice! Thank you, Larry. The predicted day and night temperatures were much lower than what actually happened, so I probably could have left all hips on the plants, but to be cautious I took about 8 cuttings with hips and currently have them in cups of water in a sunny spot indoors. Would you recommend I plant them in soil like the other cuttings I’m rooting/propagating? How many hours of artificial light do you provide them with? Is there anything I should watch out for while monitoring them? Thanks again!
When you put a rose into water, whatever hormones it produces are diluted into the large volume of water. That is unnatural for a rose. Better to put it into a moist , well aerated medium which could be sterile soil, vermiculite, peat moss or mixtures. Treating with a rooting hormone often helps some in stimulating roots. It really depends on eh CV. Some will make root within less than 2 weeks in most any condition. Others are much more finicky about it and even with help only root a fraction of cuttings.
Typically I use a quart sized cottage cheese box, or cut-off half gallon milk jug. Make sure to cut some holes to let water drain. Press the growth medium down moderately firmly. Using a big pencil, or a stick or dowel make a hole for each cutting several inches into the medium. That way the rooting compd stays on as you put the cutting in. Then press the medium around the cutting, so it is stable in place. I use five cuttings per container, with the tallest one in the middle. Cover with a plastic veg bag from grocery, securing that around or under the container so the moisture is held in.
I set this under a shoplight with plant tops about 8-10 inch below the lights. Leave lights on continually. Typically I get 4/5 to take. With some it is close to 10/10. Others can be much lower. But often they will stay green and leafed for months, just no root. When new shoots start, usually that indicates rooting success. I trim some leaflets off most of the leaves, partly to get more into the container without self-shading. And the snipping may actually stimulate hormone production, esp ethylene/auxin which promotes callousing in response to perceived injury.
In a decently warm place the hips should ripen as fast as they would in the same temps out of doors.
I don’t know that any of this cutting method works for species that prefer to propagate by root suckers. I’ve only used it for hybrids and rugosas plus Above and Beyond and some of my near species, and R. setigera. I’ve never rooted Austrian Copper successfully, though its hybrid with Carefree Beauty (Carefree Copper) does OK.I’ve never rooted Austrian Copper successfully, though its hybrid with Carefree Beauty (Carefree Copper) does OK. Decades ago I used this method with a lot of heritage roses and successfully distributed the plants to a lot of people.
Good luck with future trials.
Hi Larry. This is so helpful! Thank you for sharing your knowledge on this. I’ll go ahead and treat the cuttings with hips the same as some other cuttings I have rooting now, getting them out of the water and into soil/under lights! Who knows if it’s too late since they’ve been in water for a week at this point, but I’ll give it a shot. I really appreciate your time and advice. Thanks again! -Sue
If the stem of the cutting doesn’t begin to rot in the water you are probably OK. I have had cuttings from one rose of my own that were cut for flowers, and then stuck into soil several days later to root. I had very good luck, the same as if I had cut the flower stalk after the flower dropped. this was in fall when I don’t mind cutting lots of flowers. Also rooting cuttings indoors under lights is often easier at that time of year in my experience. This is not a new idea. I think I read about it in old Rose Annuals or American Rose magazine long before we had an internet.
Of course not all roses will behave the same. And realize a hip is very different from a dead flower in terms of what’s going on with the shoot. For one thing the leaves are a lot older, and may be richer in starch which is a plus. But sometimes they are about ready to fall off, and do sowhen you try to root them.
I tend to root most of my softwood and semi-hardwood cuttings of roses by first allowing them to callus in a small amount of water, either under lights or in a window sill–this helps to prevent foliar diseases like black spot from ravaging the cutting’s leaves prematurely. This year, I had a stem full of hips that had to be treated this way because of a stem girdler, and it callused (though it dropped its leaves anyway) even while the hips continued to mature. It is always important to refresh the water every few days, and if any bacterial or fungal funk develops on the base of the stem, to rub it off gently with fingers under running water. Only re-cut the stem in the extreme case where it blackens and doesn’t start to callus, or if you catch it starting to wilt before it has gone too far. Successful callusing often starts with the very cut end flaring slightly wider, before tiny whitish bits of callus appear. I don’t think that hormones are being leached into the water very much if at all, and once the cutting is callused well, it can be stuck as a cutting with a much shorter time to actual rooting. Some cuttings will actually start producing roots in the water, too, but those should be potted as soon as possible.
Interesting feedback about callusing, Stefan. Thank you! This will be a season of much experimenting for me!
On the callusing idea, I’m experimenting right now with a method to start cuttings using honey which I saw on Facebook. It calls for 1/2 teaspoon of honey mixed with the water and I’ve learned honey is a natural antibacterial/antifungal. May be useful in this application as well?
Honey! That’s very interesting. I know the ancient Egyptians used honey to treat wounds due to its antibacterial properties and 2000-3000 year old honey has been found preserved without mold or decay in their tombs…why not give it a shot on roses?!