A closer look at the complex art of grafting roses
I REALISE that I only just discussed the topic of growing roses last month. However, I am sure there is a bit of confusion out there on this very complex flower. Many books have been written at length on roses, as they can be complicated in terms of variety, species, and cultivars. Don’t forget there are so many hybrids being bred in plant nurseries today. This week we’ll take a closer look at grafting roses.
Rose classifications As a quick refresher, do note some of the main varieties of roses:
Hybrid tea – large flower that are often fragrant.
Floribunda – prolific flowering roses that make impressive clusters on the tree.
Grandiflora – the best of hybrid teas and Floribunda. These flowers are like hybrid teas, but the plant is bushy like the Floribunda.
Miniature – small flowering roses ideal for pot planting.
Grafting Grafted roses are actually composed of two rose plants. One plant offers the rootstock and the other the top part of the plant with the variety of flowers that we want. These two are grafted together as a new plant.
Grafting is a sure way to get the new plant to have the same genetic composition and quality as the donor plant. This was important in the fruit industry in the past, when tissue culture was not around to get the same quality of the fruit wanted. This is an asexual method of producing planting materials – the scion contains the desired genes to be duplicated in the new plant.
Grafting involves the joining of vascular tissues between the scion and rootstock. Compatibility of the scion and stock within the same genus is usually more successful.
There are several techniques involved with grafting.
Side-spliced grafting with a scion wood onto a rootstock.
Bud grafting of small buds onto a matured tree.
Whip and tongue grafting – this technique uses two cuts on both the scion and rootstocks to enable the two parts to be locked together giving it a strong union. It is important to remove the suckers from the base as these are not the true grafted plants. Grafting roses Choose plants ready for the job. In the tropics, this can be done almost any time, but the best would be after the plants have flowered.
Select the scion you are going to graft on another plant. A scion is often chosen because of its flower quality. The best choice is a young stem with leaves, that flowered recently, and with slightly hard wood developing.
Choose the rootstock plant onto which you want the plant to change. Select a healthy and hardy plant that may have failed to give good quality flowers. A good rootstock would ensure the success of the vegetative performance.
Keep both the donor and receiver plants well-watered prior to grafting. The union will be more successful if both the scion and rootstock are well watered. Remember that the success of the graft depends on the union of the cambium cells being able to match and transport the liquid to the scion.
Cut off the aerial portion of the rootstock. This involves doing a vertical spilt cut to wedge in the donor scion. This job needs to be performed quickly, otherwise the cambium cells will dry up.
Tie the union well with a plastic bandage, specially made for budding use. The secret of success here is the union must be airtight for the graft to work well.
The recommendation for rose family plants (Rosacea) would be chip budding. It is one of the easier forms of grafting. A bud rather than a shoot is attached to a rootstock to make a new plant. The choice of the rootstock with the desirable characteristics – trees with a dwarfing habit that are resistant to diseases – would usually find more success than other methods. This is the main method of grafting used in rubber nurseries, and the fruit or ornamental industry.
Do send me an email if you have any questions, comments, and suggestions.
Happy gardening.