Pruning and Feeding Roses
Pruning time is with us or, at least, will be soon depending on where you live. The best time to do it is just as spring growth starts so in warmer areas your roses should be pruned already and in colder areas you will need to wait until March or even April. It is not a good idea to wait until the new young shoots are a few inches long as this wastes the plant's energy and will delay flowering.
Volumes have been written about pruning roses, making it sound all very complicated, but it is really very easy. The basic aim is to produce a plant that will flower as freely as possible with good quality blooms and, very importantly, be an attractive shape and appropriate size.
SHRUB AND BUSH ROSES
The first step is easy. Cutting out any shoots that are dead and diseased. Spores on these stems can easily re-infect the new shoots in spring so removing them will help with disease control. Also cut out any stems that are particularly weak or rubbing against each other
The next step is where a little judgement needs to be made and is the more interesting part too as it will literally shape your rose plant for the coming year. How far down should I prune the remaining stems? This will depend on whether it repeat flowers or not and, if the former, whether it is a shrub rose or a bush rose.
Repeat Flowering Roses
Most, if not all, of the roses in your garden are likely to be repeat flowering and, as they flower on both the current and the previous season's growth, they benefit from at least moderate pruning, reducing the height by somewhere between 1/4 and 3/4.
Bush roses (hybrid teas and floribundas) are usually better pruned reasonably hard taking them down to about a 1/3 or 1/4 of their original height.
Shrub roses, which include the English Roses and Hybrid Musks, shouldn't be pruned too hard as an important part of their beauty is their (often) taller and rather more informal growth. So reduce them by about 1/2 but it could be anywhere between a 1/3 and 2/3, depending on how tall you want them to be during the summer.
Once flowering Roses
Many of the true Old Roses like the gallicas, damasks, etc. flower only once and only on the stems produced the previous year, so if you prune too hard you will get few or no flowers. The general rule with these is to take about 1/3 off and no more than half as, again, the shape of the plant is an important part of their overall beauty.
When the plant is a few years old some judicious thinning, cutting out the oldest stems, is very beneficial, it will encourage new young stems to grow from the base.
The aim with this group is to grow and cover a given area as quickly as possible therefore the main shoots will not need pruning in the first few years. The flowers are produced on side shoots that are usually 30-50cm (12-18") long. Prune by reducing them to 3 or 4 buds or 10-15cm (4-6"). These pruned side shoots will flower this summer and can be reduced in a similar way in 12 months time. This can be repeated 3 or 4 times according to the variety. Only when the main shoots are a few years old and reducing in vigour should they be cut out.
Training the main shoots is an essential part of the winter treatment. They should be tied in at angle, if possible, fanning the stems out to encourage as many side shoots, and so flowers, as possible.
Ramblers don't really need pruning, they should be left to ramble at will. If they need to be constrained, prune them the same as climbers.
Angle of Cut
The position and angle of cut has always been a major issue in the past but we certainly do not worry about it here when we prune our thousands of roses in the garden at the nursery. If you have the time and you want to get it just right it should be just above the bud (about 1cm) and at a slight angle away from the bud. This treatment may be a bit more worthwhile for Hybrid Teas and Floribundas as they can be more susceptible to die back than shrub roses
Once you have finished pruning your roses it is very important to clean up all the cut stems and fallen leaves as they can easily carry disease onto the next season. Then apply a good layer of mulch that should preferably be garden compost or well rotted manure. This will help to bury any spores left on the soil surface, keep the soil moist and cool, prevent weeds from germinating and, very importantly, feed the soil and the micro-organisms in the soil.
When spring growth starts apply a feed. There are many different types on the market but we favor the more organically based fertilisers - they are better for the soil and hence the roses and they also last longer