Floribunda roses and their predecessors (the polyantha roses) are made to do one thing: bloom a lot. What they lack in the hybrid teas’ elegance they make up for in a long bloom season, theoretically from early summer to frost, during which they cover themselves in blooms.
Floribundas in Hedges
If you just have a few floribundas growing as single plants, you can prune them in the careful way of hybrid teas.
Typically, though, floribundas are used in groups as hedges or masses as a kind of lower filler plant, as opposed to the specimen-like use of hybrid teas. This means pruning is typically less precise and less geared towards producing an architecture for the plant. It’s impractical to be too painstaking when pruning a rose hedge—there is just far too much to cut. Hand pruners will take maddeningly long; you’ll need hedge shears.
The goal of pruning these rose bushes is to keep them near the size you want, force a domed shape to let light hit all over the plant, and remove weak and overcrowded wood to promote thick, floriferous growth all over the plant. You want to do it as efficiently as possible, not pausing to be picky.
Timing and Tools for Your Spring Pruning
Wear hide gloves to protect you from the prickles. Rose is weak-wooded and you’ll be making most of your cuts on very small growth, so hand pruners and hedge shears are probably all you need. If you own loppers, you should have them with you for major deadwood pruning that there is a bit of every year.
Major pruning work on floribundas is done in the early spring. Rose canes are killed by low temperatures, so you want to delay pruning until winter has done its damage and you can see which canes have been killed. If possible, time your pruning for after the threat of coldest days and before the swelling of buds in spring.
Sometimes you don’t always get to have ideal timing, especially in spring. It’s OK to wait until later, as it just means that you’ll set back your rose’s bloom some. It’s also OK to prune too early, but you might cause extra winter damage and you’ll have to follow up with additional pruning again later in the year.
Shear the Floribunda to a Dome
Assuming you have a mass or hedge of roses, use your hedge shears. Make cuts through only the soft growth of last year, which are the thin green tips. You can’t shear through woody growth, but you’ll be shearing within a few nodes of it.
In shearing, try to turn single plants into a dome-like shape and hedges into long gently mounded shapes. This allows maximum light to hit all parts of the plant, which increases flowering.
Cut out Unhealthy and Crowded Growth
You're usually told to remove dead, damaged, and diseased wood first, but in the case of floribundas, which have a thick shell of prickly growth, shearing them first is easier and opens your access to the rest of the plant more.
Now that you have done your shearing, yes, you do have to get into the plant and remove the dead growth with your hand pruners, and loppers for larger wood. Don’t try to use shears for this part; they can’t cut wood. The colder your winter, the more dead wood there will be.
On the thinner growth, don’t worry about making the usual proper pruning cut just above a node. Just cut. Nodes are so close and growth so prolific that it won’t matter.
Floribundas have such an excess of growth every year that you should be aggressive. If something is weak-looking, cut it out. If it is crowded in near the top of the plant, or in the dense center, cut out a lot of it. If you have time to be a little more thoughtful, make cuts at varying heights, leaving growing tips at your top of the plant but also in its interior. Doing this yearly will help you keep the plant to size, as opposed to having it get slightly larger every year.
Suckers are thin, weak growth from the base of your rose, which is likely to have a graft union. You need to rip suckers off your rose.
Look carefully at the base of your plant. Suckers that sprout from the soil near the base of the plant are probably from the rootstock and must be removed. Try not to cut off the suckers. Ideally, rip them out by hand at the base. Ripping wounds the rootstock, making it less likely to resprout at that point.
Note: this step doesn’t need to be done in spring, so if you can’t be sure that the sucker is truly a sucker instead of a cane from your rose, wait. Let it grow, examine it in summer for different-looking leaves or flowers, and rip it out then.
In Summer: Deadhead and Tidy
Deadhead floribundas with your shears. Just snip them a few inches below the spent group of flowers (remember not to deadhead beneath swelling flower buds).
From time to time, a long cane will bolt straight out of your nice dome of blooms. Just cut it out as low as possible. There will be plenty more where that came from.
Your choice: consider ceasing deadheading at the end of summer. This will allow the remaining blooms to produce hips, the fruit of roses. On some roses, hips are an attractive feature that lasts through the winter. Also, some growers believe that allowing the hips to develop reduces winter kill of wood.
References: Walheim, Lance. Roses for Dummies. IDG Books Worldwide, Inc. 2000.