NEW  ROSES IN OLD BEDS

I  wrote an article for the Newsletter four years ago about  planting new roses where other roses have been growing and the  problems associated with it, mainly concerning the condition Rose Sickness or Replant Disease.

As it has been four years it has given me more time to assess my findings. At that time I planted several dozen new rose bushes in my garden where older roses were, just prior to the new  plantings. So to try to combat this Rose Sickness problem which was evident in certain parts of my garden, with many of the original bushes looking weak and stunted and with a poor production of good flowers, the main new ;planting areas were  roughly dug over and then saturated with many gallons of diluted Armillatox. A few days later I incorporated a fair  amount of old manure, leaf mould, lime, bone meal, compost and a little general faertilizer, and all this was then well dug in.

By sterilizing and adding organic matter etc. to the soil I felt I was giving the new plants every chance of flourishing, though I was unsure of the final result, especially in the long term. By all accounts if there had been little or no preparation of the nutrient deficient, disease infected ground the new roses would have grown poorly, produced inferior blooms and some probably would not have grown at all with others eventually dying sooner rather than later.

So my findings are as follows:

First  Year - The new roses grew quite well with floribunda producing  good size clusters and hybrid tea producing decent size blooms  with disease problems being minimal.

Second Year - Again growth was fairly good as was flower production, though the HT's were not as good as other HT's growing in other parts of the garden. They were a little slow into growth and there were not very many blooms in the second flush.

Third  Year - This seemed to be the year that both sets of roses were  troubled in similar ways. Much fewer stems produced and flower size was down on the H.T's as was the cluster size of the floribundas. Disease was more evident throughout and vigour was not as good as the previous two years.

Fourth Year - Overall, both H.T's and C.F. roses were disappointing. Growth was quite erratic, some bushes refusing to grow much at all with others doing fairly well though not to the size you  would expect. Disease was very evident on most of the roses. I hardly got any H.T's from those bushes that were good enough for the show bench, though the invasion of Bindweed midway  through the season was not helpful at all. Second flush of the C/F roses was poor compared to other floribunda roses in other  parts of the garden.

So my conclusion is for the first two years the roses are quite satisfactory, though they do not produce the size of bush or blooms that can be expected from young plants growing in virgin ground, but that said, the results are quite pleasing.

Through  years three and four it is a different story completely with  many of the bushes failing badly, prone to disease and not really responding to additional feeding/spraying etc. After the initial good results flowering finally diminishes dramatically.

A  couple of years ago I worked for a local man briefly, and prepared three new beds in his lawn. They were dug quite  deeply and a little compost, old manure and bonemeal was added  and worked in. The varieties planted were Elina, Loving Memory and Just Joey. The soil was the dry, sandy lumpy type so the roses were very well watered in after planting. Aftercare was rather minimal with just a little feeding, watering and  spraying, though the growth rate, thickness of stem and size and colour of leaves and blooms was amazing and better than  the same varieties in my own garden.

So it is obvious to me that roses grown in virgin soil will ;produce much better results, increased bloom size etc. than roses that have been growing in the same location for years,  or indeed in ground which has been prepared in a similar way as that which I described earlier.

I  personally have found on Rose Sick Soil that planting holes work quite well. I dig my holes about 15" wide and 18" deep and break up the bottom of the hole if solid with a fork. I  then throw in some fine gravel or such like, fill the holes with a mixture of compost, old manure, bonemeal, a little general fertilizer and most importantly soil which has not been in contact with roses before.

I  think this is the system I will now adopt, though I don't want  to have to dig too many large holes, and will probably only plant a few new roses every year or two. It is either that or  may be get an allotment or a bit drastically move house, neither of which am I keen on doing, so it looks like a case  of carry on in the same way and hope with the usual effort, care and attention that reasonably good results can be  maintained through the coming years.

Paul Evans

 

BLACKSPOT ON ROSES

Black spot is a fungus disease that appears as round, black spots on the leaves of rose plants. There may be a distinctive yellow band around the black spot and leaves may fall prematurely. Left untreated, black spot may infect young canes.
 
Instructions

   * STEP 1: Look for black spot on the leaves of rose plants. This fungus disease will appear as round, black spots ringed by yellow tissue.
   * STEP 2: Water roses only from below. Try not to get the foliage wet when you water.
   * STEP 3: Water in the early morning hours so the rose plant has time to dry during the day.
   * STEP 4: Rake up any fallen leaves from the soil surrounding the plant. Black spot as well as other fungus diseases are transmitted by water splashing back up onto the leaves and stems.
   * STEP 5: Remove any diseased leaves. Pick off and destroy any foliage that has evidence of black spot. Dispose of infected foliage in a sealed plastic bag.
   * STEP 6: Dust roses infected with black spot with sulfur powder. Sulfur will not kill the fungus spores, but it will prevent a new generation from germinating.
   * STEP 7: Spray a solution of 1 tsp. baking soda mixed in 1 qt. warm water in the early morning hours.
   * STEP 8: Spray roses with a dormant oil or Bordeaux mixture when plants are dormant (usually in winter).

Tips & Warnings

   * Black spot is very difficult to eliminate once it appears. Prevention is the best form of defense.
   * Spray organic fungicides early in the day for best results.
   * Chemical fungicides are also available for the control of black spot.
   * Always use the least toxic method of pest control first.
   * If you choose to use a chemical fungicide, always wear protective clothing and safety gear, including a long-sleeved shirt, long pants, neoprene gloves, goggles and a respirator.
 

 MILDEW ON ROSES

Powdery mildew attacks flowering annuals. This fungus thrives with heavy rainfall and high humidity, but is also caused by temperature changes between day and night. Foliage suffering from powdery mildew looks like it has a white coating of talcum powder.
 
Instructions

   * STEP 1: Look for a greyish-white powder on leaves. Plants affected by this disease include roses, zinnia, zucchini and verbena.
   * STEP 2: Avoid overhead irrigation if possible. If there are sprinklers near the affected plants, either cap them or move the plants to a drier location.
   * STEP 3: Water in the early morning hours so that plants have a chance to dry during the day. When watering plants, avoid wetting leaves. Hold the hose near the base of the plant instead of watering from overhead.
   * STEP 4: Protect plants from heavy rainfall. Place susceptible plants under overhangs or eaves.
   * STEP 5: Clean your garden of any infected plants, especially in winter, for maximum protection against the disease. Dispose of infested plants and don't compost them.
   * STEP 6: Keep the area under mildew-prone plants raked and clean. Fungus spores splash back onto the foliage during rainfall or irrigation.
   * STEP 7: Spray with a solution of 1 tsp. baking soda and 1/2 tsp. horticultural oil mixed with 1 qt. of warm water in a 1-qt. sprayer. Don't forget to spray the undersides of leaves.
   * STEP 8: Spray or dust plants with sulphur-based fungicides as a last resort.

Tips & Warnings

   * Plant mildew-resistant varieties of plants. Waxy-leaved plants, including bird of paradise, canna and aspidistra, are usually resistant to powdery mildew.
   * Although powdery mildew looks horrible, it causes little harm to the plant. Harvest your zucchini and enjoy the fruits of your labour.
   * Always use the least toxic method of control as your first step.
   * Fungicides are among the most toxic garden chemicals. Wear goggles, neoprene gloves, a respirator, and long sleeves and pants when applying them.

Planting

Bare Root: When the order is delivered, place the roots in a  bucket of water overnight and keep the roots moist at all times. If the  roses cannot be planted at once bury the plants in moist earth, in a slanted  position, until planting time. Before planting, cut back broken or damaged  roots and canes to healthy tissue.

Container grown roses: These are already growing, so when planting  always remove the pot, even if fibre type, and try to minimise root disturbance.  Cut away the bottom, then cut the pot vertically. Holding the pot, place  the plant at the correct depth in the hole, back-fill part way and peel  off the pot. Finish as described for bare root planting.

 Dig a hole large enough to permit the roots to spread out freely. Set  the plant on a mound of fine soil and spread the roots over the mound  with the bud union at least 5cm (2 in) below the finished grade.

 Back-fill the hole with soil/peat mixture to about three quarters full  and firm the soil mix around the roots. Fill the hole with water and permit  it to drain. Finish filling the hole and continue adding earth to form  a mound to cover the canes. Do this in either fall or spring: it provides  winter protection in fall and protects against sun scald in spring. Remove  the mounds when t he plants are established and the buds begin to break.