Folks searching for information about "New Dawn" rose care are among the most frequent visitors around here. So, for those who are interested, my rosarian regimen is as follows.
The subject of this attention is a vigorous eight-year old "New Dawn" bush trained to a trellis that arches over my back door.
May 1: Apply 1/2 cup of Epsom salts dissolved in 2 cups warm water to the roots of the bush. Epsom salts (MgSo4) are a good source of magnesium and sulfur. Without an extra shot of magnesium, this particular rose can show the signs of magnesium deficiency--yellowing of the leaves between the veins and leaf curling--due either to its poor soil or leaching from the nearby concrete house foundation.
June 1, July 1, August 1: Scratch a 1 1/4 cup of RoseTone around roots monthly. Up here in Zone 6, fertilizing later than August 15 risks promoting new growth that will not have sufficient time to harden off before killing frosts. Resist the temptation.
Early spring, prune out winter-killed stems and other deadwood. Climbers bloom on the previous year's wood, so limit the trimming to just tidying up.
While in flower, deadhead spent blooms for appearance.
After flowering, the bush can be shaped.
At this time, do:
*Prune severely as soon as possible in order to direct energy towards the development of new canes and to support flowering for next year.
*Remove deadwood and spindly, ill-shaped, or old canes.
*Cut back laterals, the smaller branches growing from the upright canes, on the diagonal at 1/4 inch above the first group of five true leaves. Cut so that new growth will be directed away from the center of the plant.
*Train vertical canes to the trellis by tying with garden twine.
*In order to prevent abrasion against the stem surface, form the twine tie as a figure-eight looping between the stem and the support.
*In order to avoid crushing the stems, use by-pass rather anvil clippers.
*Position canes to overlap or rub against each other, say the experts. And good luck with that thorny throw down!
*Leave rose hips to ripen.
For me, pruning requires several afternoons teetering on a ladder--never pleasant under a hot summer sun--so I don't generally get around to this task until the weather starts to cool. By late fall, the plant is no longer throwing out new growth, and laterals have been trimmed to project 3"-5" from the vertical canes.
Mulching and watering
Rosarians say that plants require about an inch of water each week during the growing season. For me, the easiest way to meet this requirement is just a a few hours with a dripping hose.
Since this rose isn't sprayed with fungicides or pesticides, good hygiene is critical to maintaining its foliage and flowers. To avoid mildews, I don't spray the leaves. Before putting down any summer mulch, I clean up old leaves and other potentially disease-harboring debris. Also helps to be willing to accept a limited amount of black spot, aphid activity, and Japanese beetle damage.
Since I lost another "New Dawn" to a particularly dry, cold winter, I am careful to winter mulch after the ground has frozen in early January. I snug up evergreen boughs from discarded Christmas trees over the base of the plant to the height of about a foot. They come off slowly in the spring as the weather warms.
And then there's the reason that this variety has been going strong since it was introduced in 1930: it's plain and simple beautiful.