Roses bloom in cycles. We are fortunate in San Diego: We have a very long growing season, and many of our roses give us four and even five bloom cycles. We can initiate faster bloom cycles and better blooms when we prune and deadhead our roses.
Learning the bloom cycle
Generally, roses bloom in six- to eight-week cycles, with some varieties requiring even less time between blooms. If you want your rose garden to be spectacular for a particular date, count back about six to eight weeks, and cut your rosebushes.
For even more accuracy, keep a log of your roses and the period of weeks between rebloom for each variety. This is what rose exhibitors do in order to maximize the number and quality of blooms they have for an show.
Goals of pruning
In San Diego, our winter pruning in January prompts our roses to produce their best quality and quantity of blooms. There are several reasons for this: First, pruning encourages our roses to be productive; second, when we prune to thicker stems, we get bigger and better blooms; and third, pruning all our roses at the same time or within the space of a few weeks of each other prompts a synchronized and magical show-stopping spring display.
Goals of deadheading
Deadheading our modern reblooming roses throughout the year encourages reflowering. The rose plant produces blooms, not for our enjoyment but in an effort to reproduce itself sexually. Once a bloom is pollinated, seed-containing hips develop and hormones are released that inhibit the plant from reblooming.
Because we grow roses for the enjoyment of their blooms, we want the plant to keep getting the message that it hasn’t finished its work of seed development. This message is relayed every time we deadhead a spent bloom. Even if a hip does not develop, a spent bloom should be deadheaded to promote a tidier and more attractive rose garden, and earlier and better blooms. Each time we remove a spent bloom, we need to make a decision as to where to make the cut on the stem.
Deadheading process
Where we deadhead depends on the season and the rose. In the spring and in cooler weather, we generally deadhead established healthy roses at an outward-facing bud eye, at the second or third five-leaflet set of leaves. We should remove less foliage on newly planted and less vigorous bushes, deadheading them at the first outward-facing five-leaflet set.
In summer, when the weather heats up, we adjust our cuts to maintain as much foliage as possible, even on healthy, vigorous plants. We cut blooms at the first outward-facing five-leaflet leaf. We generally choose a five-leaflet set of leaves over a three-leaflet set, because there will usually be a more robust bud in the leaf axil of a five-leaflet leaf.
In addition, the lower, thicker stem will a better bloom or blooming cluster than if we cut at the higher-up three-leaflet set of leaves. We use our good judgment and cut higher up on a stem or even at an inward-facing bud eye on struggling or newly planted roses. On the least healthy bushes, maintain foliage and deadhead just the bloom.
Leaving the stems longer when we deadheaded through the hotter months was good for the plant, but by summer’s end, we notice smaller blooms, leggy stems, more twiggy growth and “dog-legs” (multiple stem-on-stems). Your roses’ cycles are no longer in unison with each other because of the longer and shorter intervals of the varieties’ bloom cycles. You may feel that you need to take action to get some of that “spring magic” back in the rose garden.
Fall perk-up
In San Diego, dedicated rosarians calendar the Labor Day weekend for quality garden time with their roses. We “fall prune” our roses to shed their summer languor and help them become spectacular again.
A stem that is thinner than the diameter of a pencil will not produce the bloom or cluster of blooms we want. So, we cut thin, leggy stems down to thicker, more substantial stems and remove twiggy growth and “dog-legs.” Our cuts are made at an outward-facing bud eye at a five-leaflet leaf. We do not strip off the remaining leaves, and we do not cut as much off the height of the bush as we did in the winter.
Keep in mind that the farther down you cut each cane, the longer it will take the bush to bloom. In very hot inland areas, be more conservative and deadhead very lightly. New bushes planted this year and old garden roses that bloom only once a year should not be fall pruned.
Other fall tasks
• Cleanup: Thoroughly clean up clippings and all fallen leaves and petals. This removes fungal spores and insect eggs.
• Watering: September is still very hot in San Diego. Keep your roses well watered, especially during Santa Ana winds, and water-wash the leaves periodically.
• Fertilizing: Mid-October is the last time this year that we will feed our roses. Always water your roses before and after you fertilize, to avoid giving them leaf burn. Don’t feed your roses during Santa Anas or when it is really hot.
Your reward for this Labor Day weekend’s labor of love is a magical fall rose garden this October and November.
Perwich is a member of the San Diego Rose Society, a Consulting Rosarian and a Master Gardener with UC Cooperative Extension.
