UNITED STATES—Winter is no excuse to be less diligent in the garden. It would seem that gardening would be less demanding because there is less going on, and so many plants are dormant. However, dormancy is precisely why there is so much to do through winter. Bare root plants and bulbs are planted because they are dormant. Fruit trees get pruned because they are dormant. Now it is time for roses.

Just like fruit trees, modern roses were intensively bred for enhanced production. Their flowers are too big and abundant for overgrown plants to sustain. Consequently, aggressive specialized pruning is necessary to concentrate resources and promote vigorous growth. Rather than producing an abundance of inferior blooms, well pruned canes produce fewer blooms of superior quality.

Also like deciduous fruit trees, roses should be pruned while dormant, preferably after defoliated, and before new buds swell. This sounds easier than it really is. Some roses might still be trying to bloom on canes from last year. Others might be trying to generate new foliage for this year. Fortunately, they are tougher than they look. Besides, early or late pruning is better than no pruning.

Hybrid tea, floribunda and grandiflora roses need the same sort of pruning. They all should be pruned back to only a few canes that grew last year. Older canes should be pruned out completely, unless there are not enough new canes that grew last year. Hybrid tea and floribunda roses need only three to six canes, only about two feet tall. Floribunda roses might have a few more canes. Tree roses should be pruned just like shrub roses, as if the upper graft union is at ground level. The canes can be pruned shorter.

Suckers from below the swollen graft union (from where canes emerge) should be removed completely. If possible, they should be pulled or peeled off instead of cut. This seems harsh, but leaves less of a stub from which more suckers might develop later. Because fungal spores and bacterial diseases overwinter in decomposing foliage, fallen leaves should be raked from around roses.

Highlight: agonis

Fans of the Brady Bunch might recognized agonis, Agonis flexuosa, from the front yard of the Brady residence. That particular tree was rather dark olive green, and might have grown two or three feet annually to reach the upstairs eaves. Most of the popular modern cultivars are darker bronze or burgundy, and probably stay a bit shorter, but attain the same elegant and slender form.

The narrow evergreen leaves hang softly from limber stems, like the foliage of weeping willow. Anyone who has pruned agonis has likely noticed that the foliage is aromatic if disturbed. The tiny pinkish white flowers that bloom in spring or summer are not much to look at, but can be fragrant if there are enough of them. The fibrous and furrowed bark is quite distinguished for a small tree.

Agonis is not too demanding as long as it gets enough sunlight. It will lean away from shade. It prefers to be watered somewhat regularly through summer, although established plants can be quite happy if watered only a few times. Too much water rots their roots. If pruned to promote branching while young, and pruned for confinement as it matures, agonis can be a striking unshorn hedge.