Fertilizing New Roses

By G. R. Barse

It is said that newly planted roses should not be fertilized until some time later~ at least after the first bloom cycle. Is there a valid reason for this?

Insofar as a clearly defined reason for not doing so, there is none I can find or see. Obviously a plant needs to have available the raw materials of which it is made, some more than others. If no fertilizer is supplied, particularly nitrate, the new plant is forced to rely either upon stored nutrients, which are limited, or upon what preexisted in the planting soil, which probably is at least deficient in nitrogen. A new plant starts out with a limited root system as it is, and probably is particularly lacking in root hairs, which is where more absorption takes place.

So why put it at further disadvantage by depriving it of a readily available source of building material? There are several qualifications that should be mentioned, however. First, one must observe normal cautions and ensure that fertilizer concentration is not made so high as to cause water loss from root cells by osmosis, leading to ‘burning’ of the roots. This, however, is always a consideration in dealing with plants newly planted or not.

A further consideration stems from the experimentally observed fact that too much fertilizer tends to limit root growth. A plant’s root system will grow until it has taken in enough nutrients to support top growth. If a heavy application of fertilizer has been made, the roots will not have to grow much to support the top, resulting in a smaller root structure. Thus moderation, but not absence, would seem the best approach.

Editor’s Note: The above article is a small part of an excellent article on myths of culture written by Dick Barse, former editor of the Potomac Rose Society bulletin. It appeared in its entirety in the American Rose Annual in December~ 1998.

This article was originally published in Rose Ramblings, Vol. LXXII, No. 3, March, 1999. © 1999 San Diego Rose Society, Inc.

Keywords: Feeding