After the blog I wrote a few weeks ago about cataloguing the Sissinghurst roses, a reader asked if I could share how we plant our roses here in the garden. As it’s still rose planting season for bare root roses, I thought this might be a useful topic to cover.
Container grown roses can be planted at any time of year but at Sissinghurst we only plant bare root roses, which must be planted during their period of dormancy in winter. There are a few advantages to using bare root plants, the main ones being that they are cheaper and have time to establish their roots when there is plenty of moisture in the soil and they are not putting their energies into making leaves or flowers. When spring arrives, the rose should be able to grow away quite happily without needing too much attention from us.
Soil preparation is important. We always dig the area thoroughly, adding homemade compost to the soil before digging a hole that’s large enough to comfortably accommodate the roots, ideally twice the width of the plant’s roots. As a rule, we try to avoid planting a rose where one has previously grown because of rose replant disease but we can sterilise the soil if necessary. However, as a home gardener, sterilising is probably not an option for you, so you will have to choose a new spot for your rose. If the soil is wet, check that a ‘smear pan’ hasn’t been created by the spade and use a fork to loosen the sides and bottom. We also add some bone meal to the bottom and lightly fork it in.
Bone meal is high in phosphorus and calcium, nutrients that are particularly important in root growth and often difficult for plants to access. However, research has shown that soils high in phosphorus may actually suppress mycorrhizal fungi in the soil and the RHS now do not recommend the addition of phosphorus rich fertilisers, so it’s likely we will be reviewing our own practices soon. You can read more on these two links:
Once the hole is perfect, attention can be turned to the rose. Check the roots and if they are dry, soak them in a bucket of water for a while. Ideally a rose should be planted as soon as it is delivered but in real life that’s not always possible and roses quite often end up waiting in the wings until either the right weather arrives or planting fits in with our schedule of work. If the rose isn’t going to be planted for a while, just heel it in to stop the roots drying out.
Once ready to plant, we make up a solution of mycorrhizae, mixing the granules with the correct amount of water and a thickening agent to make application easy. A good consistency is like custard that will pour from a jug. This will coat the roots and stick to them but not form big clumps. Dip all the roots into the solution and coat thoroughly. Mycorrhizae are beneficial fungi that form a symbiotic relationship with the roots of most trees and plants. In return for sugars from the plant, mycorrhizal fungi will form an extensive secondary root system for the rose, infiltrating large areas of soil and allowing the plant to access extra nutrients and water. These extra nutrients and the ready supply of water allow our roses to become established quickly. Once the roots are thoroughly coated, place the rose in the hole ensuring that the roots are well spread out and that the graft union (where the cultivar joins the rootstock) is below the soil level. You can use a small cane laid horizontally across the hole to check that the union is at the right level. When happy, return the soil and firm well.
Always water even if the soil is moist as it helps the soil particles settle around the roots and gives the roots immediate access to water. We then give a final top dressing of compost. Either label your rose or note the name for future reference. This is particularly important if you are planning to plant a few different roses. Finally, lightly prune the rose stems to an outward facing bud and then wait patiently for your rose to grow and flower.
If you want to have a rose in your garden but don’t know which one to choose, why not visit Sissinghurst in June and find your own personal favourite. Planting is easy; choosing your favourite is the real challenge.