May-July in the Rose Garden

This Quarter in the Rose Garden May-July

Dave & Sandy Long

The garden is OPEN! Yes, spring has arrived; the forsythia bloomed a little earlier than usual – at least in the Hartford area. For those of us who live in the shoreline area, the forsythia opened a little later then usual. The late winter seemed to have steady temperatures but the unusually cold winter temperatures (minus 15 degrees on two mornings), caused a good deal of cane dieback. By the time you read this newsletter, you should have already pruned out all dead wood and the blackened dieback canes. You should have made your first fungicide (Mancozeb) spraying when leaves first developed. Roses should be uncovered and hardening of tender growth should be well on its way to developing new stable canes. Your first granular fertilization should have started the last week in April into the first ten days of May. Ground temperature will dictate if the rose will take up the nutrients. Cold soil will limit the roots absorption rate. You will have to make a judgment decision on when to fertilize based on your experience and your own ‘micro climate’. Many growers start the season with a liquid fertilizer of their own making or one of the commercial varieties. Granular feeding of general purpose 10/10/10 fertilizer is fed starting in late April to early May and then once a month through July. Three-quarters to one cup is sufficient for established bushes. Newly planted bushes should wait a month before starting the fertilization.

You might consider the use of Messenger in addition to your fertilization program. Messenger is derived from a naturally occurring protein (harpin). The manufacture’s literature states to ‘Use messenger to boost overall plant growth, vigor, production, and to aid in the management of disease’. The manufacture would like you to use it every 2 to 3 weeks. I have used it the past three growing seasons with very good results and I only used it on two occasions each year. Bushes seemed healthier. Blooms and leaves were larger and more vigorous.

CRS members have usually followed a tradition of spring pruning hybrid teas down to one foot. Floribundas, grandifloras, minifloras and miniatures are shaped to the owners desires, but pruning down to where the cane is the diameter of a pencil is not a bad rule to follow. Again, your experience will dictate over time. Sandy and I like a ‘wild and wooly’ – if you will – appearance. Why cut the shrubs, grandifloras, etc. down to two-thirds their height and force them to grow back up to where you want them? We like to let them grow first and then cut back after the first blush if necessary. Consequently, our David Austins, hybrid musk, floribundas, grandifloras and climbers tend to be full, rangy and floriferous.

The month of May seems to bring the insects out of their hibernation. You may experience rose midge, aphids, thrips and spider mites. Control of spider mites can often be accomplished by direct spraying of the affected areas with a strong stream of water every couple of days. You can use a water wand and make sure you concentrate on the underside of all leaves. The mites multiply quickly, so frequent sprayings may be necessary. We had a serious infestation of spider mites which were imported into our garden on newly purchased bushes. We sprayed with water but they multiplied faster than we could spray. We ended up purchasing Floramite SC from Rosemania and that did the trick. Floramite has a 21 day residual effect and just a couple of uses all summer long and mites were no longer a problem.

Educate yourself about Integrated Pest Management (IPM). The key to this pest management program is the Identification of which pest is causing the problem. Do your research and use the recommended pesticide for the condition identified. See articles in www.ctrose.org on IPM, fertilization, soil and etc… Other tools include purchasing a Consulting Rosarian Manual from the www.ARS.org store and checking out www.rosemania.com for articles and products.

Rosemania handles a product called Conserve SC. The active ingredient in Conserve is spinosad, a soil dwelling bacteria. This product is great at combating thrips, army worms, bag worms and bud worms, but it does not harm any beneficial insects or predatory mites (the mites that eat the spider mites). For this reason, Rosemania says the “Conserve is the ‘exception to the rule’ and may be used preventatively”.

Many rose growers like to use various types of bark mulch up to a depth of 2 to 3 inches to control weeds and help to retain water. We have had problems using the bark mulch because voles and moles like to make their homes in the nice moist environment and then attack the roses, perennials and annuals. We do live on the edge of heavily wooded areas and I think this defiantly contributes to the infestation. We are fortunate to have access to horse and cow manure. We also compost leaves, grass and vegetable table cuttings. I screen the manure and compost on a one-to-one basis into a wheelbarrow and use this as our mulch. During the course of the growing season we will add a couple of shovels of mulch to each bush when we do our monthly fertilization.

Rose bushes, like most of us humans, like to eat and drink (water that is). June and July can be very hot and dry. The rule of thumb has been that roses need at least one inch of rain on a weekly basis. This may not be enough. In fact if we only receive one inch of rain during a particular week, I will start watering up to a third of my garden on a daily basis. This is very essential during the preceding weeks leading up to the Rose Show. Some exhibitors like to foliar feed with a liquid fertilizer a couple of weeks before the Show to give an extra boost to their blooms.
July can see the emergence of Japanese beetles. Please, do not use Orthene, which is recommended by some to kill Japanese beetles. It has been shown that Orthene does not kill the beetles; besides it is harmful to bees and it has a negative effect on natural predators. Also, do not use a bag-a-bug in your own yard. You will have all the Japanese beetles in the neighborhood living in your garden. Some gardeners flick the beetles into a water bottle – we use the ‘digital squeeze’ method – it is fool proof. Every second or third year we put down a grub control on the lawn areas. It does an effective job of controlling the grubs and reducing the mole population.

We encourage everyone to enter the Rose Show. You don’t know what other exhibitors might bring. Don’t discourage yourself by saying ‘this is not good enough to win anything’. Your entry may be unique but you won’t really know unless you enter. See each of you at the Rose Show!