Grafted roses are created by inserting a bud eye under the bark of the cane of the understock. Rosa multiflora is the preferred understock in our region because of its cold hardiness and ability to encourage vigorous growth. The newly grafted rose is planted out in a field. Once the bud has produced enough growth to support the newly created plant, the section of the cane above the graft is removed. The plant is dug up in the fall, soil is cleaned from the roots, the new growth is pruned back and the rose is placed in cold storage until the following spring when it is sold.
Grafting gives you a larger plant as you are planting a rose that has a two year old rootstock. Some varieties are more vigorous and healthy when grafted. Grafted roses “stay put” in the garden. They do not spread by suckers or runners. Unfortunately, if the top of a grafted rose is destroyed, you have lost the plant and the understock will take over.
Grafted plants can be purchased bare root or potted. Bare root plants need to be planted in the ground or in a large pot as soon as possible after purchasing. Contrary to what is common practice, the graft needs to be planted 3-4 inches below ground level in zones 5 or below. Over time, the part of the plant above the graft will root on its own and the understock will die. Planting this deeply prevents wind rock in the winter as the plant has multiple points of contact with the ground rather than just one stem. A trick I figured out in planting grafted roses is to plant them at an angle. You don’t have to dig as deep a hole, although you have to dig a wider hole. Grafted plants often have lopsided growth as the graft is on one side of the stem. By planting it at an angle you take advantage of this growth pattern.
Own root roses are rooted cuttings. Most nurseries typically sell one year old plants in band pots (about 2”x2”x6”). This size keeps shipping costs lower. These plants take about two years to catch up to a grafted plant. If the top of an own root rose is mowed over, broken, chewed by deer or rabbits or otherwise damaged, it will resprout from the roots and come true. Own root roses can form clumps or runners depending on the variety like many perennials.
I have found own root roses do best if planted in a larger pot rather than in open ground when first purchased. I use one gallon Rootmaker pots at this stage (www.rootmaker.com). These pots encourage quick growth of very fibrous roots. When the roots have filled this pot (usually within a couple of months), I move them up to a two or three gallon pot. It is worth the extra effort of gradually increasing pot size. I keep the own root rose in the larger pot for another two to three months, until their roots fill the larger pot. Then, they can be planted in a permanent location. Starting with an own root plant in April or early May and following this procedure, an own root rose can safely be planted out in September. This gives the plant the fall to establish its root system in open ground. Roots will grow as long as the soil temperatures are above 45 degrees or so. The following spring the plants are ready to take off.
As most folks are not interested in taking the extra time and care it takes to grow on an own root plant, I grow my cuttings to two or three gallon size before selling them. I offer both grafted and own root plants in my nursery. If you walked around my gardens, you would not be able to tell which rose was grown from a cutting or which was grown from a grafted plant. Nurseries sold own root plants many years ago but moved to producing and selling grafted plants because the reduced cost of production. It takes only one bud to produce a grafted plant. A cutting used to create an own root plant requires rooting a section of cane that has at least 6-8 buds.
So which do I recommend you buy, own root or grafted? I don’t think it makes that big of a difference. If you can only find the variety you want in a grafted plant, remember, you can take cuttings and grow an own root plant yourself later on. But that’s a topic for another blog.