First frost sets garden agenda

Ruapehu Bulletin, Volume 12, Issue 586, 16 May 1995, Page 8

First frost sets garden agenda

The first really hard frost of winter has arrived. This will finish off all the dahlias ~ a pity as they have flowered so well with all the lovely warm weather. All that sad looking blackened growth is best removed as soon as possible. If you lift your dahlias for winter storage make sure they are really dry before you store them. There is still time before winter sets in to divide over-large clumps of perennials or to transplant them as necessary. If it is inclined to be frosty this will be best done earlier in the day so that after you have watered the plants in, the water will have had time to drain away. Deciduous trees or shrubs should not be moved until after leaf-fall when they are in their dormant period but evergreens can be moved now. Most of the smaller growing shrubs and a lot of the conifers have a balled-root system and can safely be moved to a new position with a little care. Dig carefully around the perimeter of the shrub to be moved to determine the size of the root-ball. Work around the shrub until you can lever the whole plant clear of the ground. Lift it out and transfer it to the new position and water well. When repositioning shrubs or trees it will be of greater advantage to the plant if it is replanted facing in the same direction as it was in its former position. If in transplanting the position is reversed the plant may appear to 'sulk' and put on no new growth at all in some cases for quite long periods.

In the case of large plants they may even die. Apparently each shrub or tree arranges it's cell structure according to the environment in which it is growing thus ensuring even growth all round the plant. This is all to do with the sap run of the plant and if it is completely reversed it has to reorganise the sap run before it can begin to grow again. Last call for tulips The month of May is the latest time for planting your tulips for a good show in spring. Some of the spring bulbs planted earlier are beginning to show green shoots through the ground now. As the weather cools and winter takes over you will find that the growth will slow considerably and the bulb will flower at its proper time in the spring. If , however, the weather remains very mild then they will flower a lot earlier completely out of season. This is the month to plant your new liliums and to divide clumps which have become too large. Liliums do not take kindly to having their roots disturbed and unless it is really necessary are best left where they are. Liliums of the Asiatic variety, smaller and often with more and brighter flowers than some of their more exotic relatives, do very well in this climate. They make a bright showing and there are some new varieties on the market, some ideally suited to pot-culture.

Roses are still blooming although I think one or two of the harder frosts will slow them up ready for their long winter rest. In this area full pruning should be left until late July or August depending on the weather. At this stage a general tidy-up will suffice, removing any die-back on the ends of the stems and pruning broken branches back to a healthy bud. Any very tall stems can be reduced in length by about a third or even half to prevent wind-rock during the strong winter winds. The plant being rocked by the wind can cause gaps in the soil around the roots where frost can creep in to damage surface roots. When the plants go into dormancy a spray with winter oil will help to prevent disease spores from over-wintering in the soil and give your plants a clean start for the spring. At this stage you should have a general clean up of the bed removing all weeds which will go rank and damp if left in for the winter. Lightly hoe the soil to let the air penetrate taking care not to disturb the roots which can grow very near to the surface. If, like me, you prefer to give your roses the protection of a good layer of mulch for the winter, blend this with a dressing of horse manure which will help to improve the structure of the soil and replace any loss of nitrogen leached from the soil as the mulch slowly breaks down.