Caring for roses after a wet winter

What a year it's been so far. In most areas, gardeners had to work in a pruning schedule between rain storms. Even with late pruning, many gardeners are having or are about to have their first flush of blooms. Climate change is influencing the weather and effecting the usual pruning schedule. The erratic temperatures also have a bearing on the growth of plants.

Periods of heat encouraged lush vegetative growth and bud formation even though rains kept the soil cool. Now the conditions for fungi are present and rust and mildew which will need control with fungicides and stripping infected leaves if the disease is heavy.

For the fullest blooms possible, supply plenty of water to plants, but don't flood them. For larger blooms apply a greater amount of water when buds begin to swell and show color. But pay attention to the drainage of the soil – roses like plenty of water but they don't respond well to soggy soil. The optimum time to irrigate is early in the day.

Roses love food. Preferably good quality food on a regular basis. Not all fertilizers include all the micro and macro nutrients needed, so read the label on the packaging. Alternating the major fertilizer with fish emulsion every two weeks will help provide some of the micro nutrients. Continue fertilizing.

As I always say, organics are much better for soil and ultimately for the garden and the environment. Adding 1 cup of Epsom salt, which is magnesium sulfate, to large size plants, 1/2 cup for smaller plants, once in the spring and once in the fall can assist in getting new basal breaks, the new canes from the bud union.

The soil needs a supply of organic material such as hummus incorporated into the depths. That supply isn't easily accomplished in established gardens, however adding a 3-4 inches of a good composted mulch over the entire garden, leaving a 12-foot diameter circle open around the base of each bush will go a long way to enriching the soil overall because earthworms help transport that mulch down into the soil where the microbiology is complex and multi-tiered.

A healthy garden soil system is teeming with beneficial microbes that inhibit, compete with and consume disease-causing organisms. This environment creates a sustainable soil "immune system." In fact, plants grown with organic fertilizers are themselves more resistant to pests and diseases. In addition, when gardeners feed those beneficial organisms, they feed the garden's roses because they are busy breaking down organic matter and releasing mineral nutrients slowly and reliably.

I've recently learned that extra phosphate in the fertilizer used is the most important in assisting in creating a soil environment that aids immensely in helping plants to be resistant to pest and diseases. Also it helps plants to develop hardier root systems and larger blooms.

Many gardeners become discouraged when they first experiment with organic treatments while still using chemical fertilizers. It is difficult – in fact, almost impossible – to have it both ways. Chemical fertilizers negatively impact the soil food web by poisoning entire portions of it. The fact is, chemical fertilizers are salts. What gardener hasn't seen what table salt does to a slug or snail? Salts absorb water and dehydrate the soil microbes which are the foundation of the soil nutrient system.

Once a chemical fertilizer has been used regularly they must keep being added because the soil microbiology is weakened and unable to do its job of releasing naturally available nutrients to the plants. Rains help to leach accumulated soil salts from the soil, provided there is sufficient good drainage.

Organic fertilizers and amendments such as manure, compost or mulch break down slowly, generally staying where they are put, and they don't contribute to groundwater pollution, as long as the gardener prevents the run off from going into the drains. In addition, they improve the soil food web, so in the long run it ends up using less product.

Chemical fertilizers are artificial growth stimulants and, in the long run, harm the soil and pollute local waterways because as dissolved salts they quickly leach through the soil becoming unavailable to plants and enter the groundwater. How about swearing off chemical fertilizers for the rest of the year and starting to use organics? Give it a year. The results are rewarding. Fish emulsion is also a good amendment to apply either foliarly or onto the soil around each bush.

It may be that a rose bush has some blooms already. Keep spent blooms cut away. Cut the cane back to an outward facing bud at a 3-5 leaflet leaf for new growth. Air circulation is important to help prevent fungi diseases. The small spurs growing inside the bush can easily be finger prune to keep the center of the bush free of extraneous growth.

Giving the bush an early morning shower to rinse off the leaves may help to avoid powdery mildew. Do this early enough that the leaves will dry before the hot sun arrives. It is possible that with nighttime dew a disease called botrytis can appear on the blooms, especially on blooms with 40 petals. Remove these as soon as disease is noticed.

Even with great observations and preventive methods, fungi may become a problem and chemical treatment may be needed to keep disease at bay. Make sure to deep water. An extended slow watering is more beneficial than a frequently short application.

There are many opportunities in the next month or two to attend local rose shows and see, learn, smell different varieties. The Pacific Southwest District Rose Show and Convention held in L.A, Arboretum is April 26-27, and the San Diego Rose Society will hold their 92nd annual Rose Show, May 4, Ronald Reagan Community Center in El Cajon.

For more ideas, visit TVRS' Rose Haven garden at 30592 Jedediah Smith Road in Temecula or visit http://www.TemeculaValleyRoseSociety.org/index.shtml.