I'm finding that certain roses need it and others don't require it, but I do it anyway because like you, I think they look more tidy without the spent blooms.

Like Kim mentioned on the recent "minis" thread, the miniatures don't need it at all. I think all of mine are relatively self-cleaning.

Most of my Kordes roses show exactly where they want to be deadheaded, with new growth sprouting before the terminal bloom is spent. I'm assuming I could just let those go. Many others, however, won't sprout new growth until after I deadhead.

I'm imagining I have a much shorter growing season in zone 5 Illinois than you do, so I try to coax as much seasonal growth and new blooms as I can each summer by tidying up the spent blooms.

Very interesting. I always figured that the deadheading just hastened the re-bloom by directing energy away from the old spent blooms, but you are suggesting that some roses simply won't rebloom at all if you don't deadhead? Is there a particular category that those roses fall into? I am going to have to pay more attention.

It is definitely true that some of my roses are more helpful in showing me exactly where to cut by having already thrown new growth, but I never was aware of the deadheading being more than a shortcut to new blooms or an avoidance of hips (which I do love, so I stop deadheading at the end of the season)...

Susan

I also do it for aesthetic reasons. But it may affect bloom as well.

Depending on the variety, roses may set no hips, a few hips, or a great number of hips. Roses that set a great number will certainly grow faster and repeat better if they are deadheaded. If they are not deadheaded, some of those hippy roses will still bloom fairly well, others very little. The plant pumps a lot of its food energy into the hips.

Michael hit the nail on the head. If no hips are formed, no energy is spent on the dried up flowers/peduncles/ovaries. If "fruit" is set (hips), the plant is pregnant. Hormones are produced, energy is spent to ripen the hips to create seed. Removing the forming hips prevents the pregnancy hormones (and other chemicals associated with pregnancy) and the plant continues ovulating (flowering). Some do both equally well simultaneously, such as Rugosa. Others will refuse to flower if they set hips at all, much like New Dawn does in my climate.

Removing spent flowers which would otherwise result in hips stimulates repeat flowering and more growth. If your climate is harsher, with a shorter growing season and more severe winters, the benefit of not removing the hips later in summer or early fall would be to trigger the plant to "harden off", not create new, soft, sappy growth which would probably be frozen off or broken more easily by snow fall.

Of course, removing the "spent Kleenex" flags from all over the plants does make the whole look tidier, more well kept.

I've not read any studies to support it, but it would SEEM to me that allowing hips to form at the height of summer might slow growth and reduce water needs when it gets very hot. There wouldn't be the increased soft, sappy growth needing high levels of water to support. Not that you should cut back on watering, but perhaps the plant wouldn't require as large an increase during the heat if it didn't have so much soft growth to support? What do you think? Kim

And, so.....do certain classes of roses set or not set hips? Is the information about which ones do and which ones don't documented anywhere on a regular basis? Or....(my best guess) should I just be paying more attention to my own and trying not to be embarrassed that I don't already have this information firmly in hand???

A list of hippy and non-hippy roses would be excellent but ....unlikely, right???

Susan

Generally roses with a great number of petals set few or no hips, because the sexual parts have mostly been converted into petals, or they are physically inaccessible to pollinators.

Once-bloomers that set hips are normally allowed to do so because the hips provide some late-season interest.

Often, hip set is environmental as well as genetic and physical. Iceberg virtually never sets hips in the warmer areas here in SoCal, while in more coastal climates, it sets regularly. Mermaid is known to be sterile, almost never setting hips, yet right on the water in Pacific Palisades, it set frequently. Nothing ever germinated out of them, but they set.

Rosarium Uetersen in high heat, has no sexual parts. Everything in the flower is transformed into petals. In milder times of the year and in more coastal climates, it is semi double and extremely fertile. As Michael said, the more double the flower, the fewer the hips set, partly due to the physical barrier of so many petals preventing fertilization as well as the reduction of the number of stamen, hence anthers and pollen by the increase in the petals. Petals are modified stamen so when you increase the number of petals, you do so at the expense of the number of stamen. Often, as in the case of moss roses, the more double they are, the less fertile the pollen is found to be. That was one of the major stumbling blocks Ralph Moore encountered and fought all those years in his attempt to create moss miniatures. Conversely, roses with fewer petals tend to be far more fertile. Exceptions being Mermaid, as mentioned before; Banksiae, even the single ones which seldom, not "never" but seldom set hips; Sally Holmes (in my climate) which CAN set them, but most frequently doesn't. There are more, but these come to mind easily.

Annie Laurie McDowell virtually never sets hips. Grandmother's Hat in my climate virtually never sets hips. Jacques Cartier never sets hips, nor does it have viable pollen.

Sometimes, the registrations will state whether fruit has been observed. Often, the patent information contains that kind of description, too. Even those can be incorrect for your climate. Sequoia stated in the registration for Splish Splash (NEAT mini, BTW!) "no fruit observed", yet it has set fruit regularly at my sister's house in Newhall for the past ten-plus years. Then, you have mutations. Crested Sweetheart is so double, it has so little pollen and what it does have is so infertile, it never set hips. Yet, toward the end of Sequoia Nursery, it sported to a branch which sets hips. Being once flowering, it didn't make much of a difference, except for the tidiness of the plant's appearance.

So, if sterility is what you want, go for those which have hundreds of petals, presuming they will open in your area. Kim

I deadhead incessantly. I can't walk past a rose with out popping off the spent blooms. I've been known to deadhead other people's roses without even thinking about it. The first year I tried doing some crosses of my own I unthinkingly popped off some of my crosses! I had to put big red bows on them to make sure I wouldn't remove them after that, lol!

Susan, I do think it makes everything look neater and cleaner. And I try to do it before the petals drop to keep the beds cleaner too. Besides, I photograph everything like crazy and that lovely fresh bloom looks terrible with the spent, half the petals dropped hip next to it or in the background.