When to Prune

You will feel a strong urge to do something to rosebushes right after they have stopped blooming.  Resist it.  It is after they have done their work that they rest and collect their starches and sugars and go into dormancy.  Without this period bushes can't store all they need.  Where my bushes grow, roses never really go dormant; the climate is too mild.  Even so, the process is similar and the resting time necessary.

For modern roses the pruning debate centers on winter versus spring pruning.  Those in favor of winter pruning point out that bushes cut back early have a chance to adjust to their new shape and size, without supporting wood that's going to come off anyway.  Those advocating later pruning point out that tender new growth can be brutally affected by late frosts and unseasonable cold spells.  Listen to what Vita Sackville-West, an ardent rose grower herself, had to say about the subject:

Argument still rages in the horticultural world about the best time of year to prune roses.  According to the old orthodox theory, the time to do it was in the second half of March or in early April.  Present-day opinion veers more and more strongly in favour of winter pruning.  It seems to me common sense to cut the plant when it is dormant, rather than when the sap has begun to rise and must bleed the wound.

I know there are objections.  People say "Oh, but if you prune your roses in December or January, they may start to make fresh growth in the mild weather we sometimes get in February or early March, and then comes an iron frost and then what happens to those young tender shoots you have encouraged by your precipitate pruning?"

All I can say in answer to that is that you will just have to go over your roses again and cut away all the frost-damaged shoots back to a new eye lower down the stem.  You might have to do the same thing after a March pruning, so you will not have lost any time, and on the whole I am on the side of the winter pruners.

Of course, one must remember that Ms. Sackville-West was growing roses in England, where winters are severe.  For most of us, controversial pruning months occur farther back in the calendar year.  For instance, where I live, near the coast in northern California, there is argument whether to prune in December, January, or February, but all agree that pruning should be well over before March.  In colder climates, pruning can be contemplated no sooner than late March.

I've experimented with both approaches.  I've pruned half of the bushes of one variety early and the remainder some seeks later.  They bloomed at about the same time.  The only differences were the slightly longer stems and somewhat larger blooms produced by early pruning.

I now begin pruning the day after Christmas.  First, I have some extra time then.  Second, we never know how erratic the weather will be for the next two months.  If the sun is shining, we prune.  Besides, we have several thousand huge bushes staring us in the face and simply must begin as soon as we can.

My advice in sum:  Prune as soon as possible once dormancy is safely broken, that is, when you're sure there won't be another hard freeze.

Ask your consulting rosarian for ideal pruning dates for where you live.  County agricultural extensions usually have a suggestion, since all dormant plants, not just roses, need timely cutting back.  Also, find out if there are any pruning demonstrations being given in your area.  Many rose societies prune roses in their local municipal gardens and give informative lectures while they're doing it.