Rose Roots

 Few roses are grown on their own roots because of the slow and usually inferior rooting of many varieties from cuttings.  A special kind of rose which does root easily from cuttings is used for the root system and the desired varieties are grown on this by the process of budding.

 Budding is a grafting technique, producing roses like those in the market place which have one type of rose that produces the flowers grafted onto another that is a vigorous root stock.  There is no one type of rootstock that is best for all parts of the world.  Some do better in alkaline soils and warm climates, while others prefer acid soils and frequent watering.  Rose producers select a root stock that is best for their conditions.  The best rootstock for our area is Multiflora or Laxa/Canina stock used in Europe where they experience similar weather conditions to ours here in Coastal B.C.

 The plant providing the root system for a grafted rose bush is called an understock.

 The understocks in current use have been selected by growers for their compatibility with the roses grafted upon them, their ease of rooting from cuttings, or their rapid development and ease of culture after seed germination.  Many of the popular roses are complex hybrids that do not root easily.  Bud grafting these roses onto understock is the most common method for producing plants for sale.  The exception is miniature roses.  These are more easily grown from cuttings.  The miniature standard, or tree rose must of course be bud grafted.

 There are three major types of rootstocks used in North America for our garden roses.  “Dr. Huey”, is used in the Southern U.S. because of its’ ability to stand high pH levels in the soil, the arid conditions and an opinion has been expressed that this rootstock does not require a long dormancy period which is desirable in the Southern U.S.  However, this is not a desirable feature in this area.

 Varieties of “Mulftifora” are the major type of rootstocks used in the cooler climates because of its preference to cool, damp, acid soils.

 “Rosa x noisettiana “Manetti” is primarily employed where the resultant plant is to be used for greenhouse forcing.  ( In our area, most of the greenhouse roses are own root plants where several cuttings grow in the same pot ) It produces more and better blooms for a prolonged period under forcing conditions.

 Understocks are either grown from seed, or cuttings in carefully prepared soil in the growers field.  Rootstock varieties are extremely vigorous, requiring only minimal amounts of fertilizer to grow.  Their needs are sunshine and copious amounts of water.

 Throughout July and August the understocks are grafted with bud eyes from the desired variety of roses.  After budding, the plants continue to grow for the rest of the season, storing sugar and starches in the root system.  The following spring, towards the end of the dormant season the tops of the understock are removed, leaving only the root system with its stored nutrients, plus the graft or bud that was inserted the previous summer.

 In early spring the grafted bud begins to grow, and for the rest of the season the plant is left to grow in the field, requiring fertilizer, water and protection from disease to insure a good quality plant at harvest time.

 In the first year, the rose is referred to as a “maiden Plant”, and will continue to grow in the field for another year.  The plants are harvested in October or November in their second year and are either sold bare root at this time or put into cold storage where the temperature is maintained just above freezing to keep the plants completely dormant.

 Finally, the rose plants reach us in a variety of ways.  Mail order nurseries provide bare root roses shipped in sealed poly bags.  Some plants are root wrapped in moisture holding material and placed in poly bags which are then put into colourful boxes and sold at garden shops or supermarkets.  The roots have been drastically reduced in order to fit into these small boxes, and are not recommended.

 Many years ago, some nurseries would order plants from Eastern Canada as well as import some from the U.K. which they sold bare root or planted in containers, extending the planting season into late spring and early summer when bare root plants would not thrive. 

 The bad news for us here in British Columbia is that as far as I’m aware, at this time most if not all of the roses in our local garden shops are roses from the U.S. and these are mostly on Dr. Huey rootstock.  When we wish to have roses on the most desirable rootstock, mail order roses are our number one choice. 

 Some roses do very well on their own roots, most of the vigorous shrubs, old garden roses, climbers, and of course miniature roses can be grown quite satisfactorily on their own roots.  Miniature roses budded onto a rootstock usually produce more vigorous growth than an own root counterpart. 

 Valley Rose Club