When we think of a particular garden variety of any plant -- a rose, say -- we have an image in mind, but it may have nothing much to do with reality.

It is generally agreed by rose fanatics (to give an example) that of two quite similar red rugosa roses, 'Roseraie de l'Hay' is better than 'Hansa,' since the first is more velvety, has a better shaped flower, blooms more steadily through the summer, has a better perfume and makes a more shapely bush.

Once a gardener gets this firmly in mind he will go for the first rose, will ignore or disparage the second, and -- here is the danger -- fail to notice any plain contradiction of his notions by Nature herself.

This year I cannot help noticing that 'Hansa' is distractingly more beautiful than 'Roseraie de l'Hay.' The texture of the petals seems the same in both roses, and there is nothing to choose between the scents. But the flowers of 'Hansa' are conspicuously more beautiful, resembling a semidouble reticulata camellia, full of grace and style, while 'l'Hay' resembles a shaggy collection of scraps of crimson-purple.

The disturbing truth (disturbing because it reverses accepted judgment) is that I have never seen a rose more beautiful in the individual open flower than 'Hansa' this spring. Evidently the long spring drought has suited it perfectly, permitting the buds to develop into large flowers of elegant camellia shape rarely seen in this variety.

Another example is often seen in daffodils. Everybody who has grown very many varieties has been astonished when some garden variety quite surpasses itself in beauty, or when some proven show-stopper produces flowers quite inferior.

The old variety 'Lord Nelson,' a yellow trumpet, one year bloomed in such beauty that nobody recognized it. The same year, the year 'Empress of Ireland' was first seen by us in a dealer's garden, when this white-trumpet variety was very new, the 'Empress' produced flowers inferior to the much older white 'Cantatrice.'

And in irises this variation is an almost regular occurrence. One year I saw 'Radiant Light,' an orange blend, in the garden of Orville Fay, its breeder, and it was so fine I ordered a root on the spot, to be delivered as soon as the variety was introduced on the market. I grew it six years and never had a decent bloom. That variety was as glorious as I judged it, no doubt of that, but it just happened that vagaries of weather and environment kept it from showing anything approaching its inherent beauty.

A noted iris judge was in my garden some 25 years ago and was struck by a magnificent clump of the old white iris 'Purissima.' This was an old kind even a quarter-century ago, and I kept it because of its enormous influence in the breeding of fine irises. Virtually every award-winning tall iris of today has 'Purissima' in its parentage. But at the time I speak of, this iris was quite inferior to the other good whites of the day, in suboping to find that one flower in 50 that surpasses the rest.

One year I cut a dozen daffodils the morning of a show and won 10 ribbons, most of them blue. It just happened that the weather (and the show date) was perfect. Years in which the gardener can go out and cut almost at random and expect to win ribbons are roughly twice in a lifetime.

In the spring of 1971 I had several stalks of the yellow iris 'Foxfire' that astonished even me (sentimentally devoted to this 35-year-old variety because I so admired Ed Fox, its breeder). Its substance was twice as thick as usual, its stems taller (usually it is about 40 inches) with more than the usual seven flowers to a stalk. I have grown it for 35 years, but only once did I see it as it bloomed in 1971.

This phenomenon accounts for some very strange awards to garden flowers such as irises. In fact, the habit of a particular flower to vary according to weather and climate is so well known that most florist flowers (by which I mean those that have gathered fanatics into clubs to promote them, such as peonies, irises, roses, primroses, daffodils, lilies, etc.) theoretically can only gain high awards when they perform handsomely over several years in various climates.

Even so, if iris judges show up in the breeder's garden the day one of his seedlings is blooming in total glory, the flower may gather so many votes from judges that fanatics all over America will buy it immediately, and this wide distribution (judges in a dozen geographic areas will be exposed to it, instead of just the judges in its home garden) may get the flower off to a roaring good start. In general an iris or any other flower with high awards will be extremely fine. But an equally fine one, not widely distributed, will wind up with a minor award or none at all, simply because judges did not see it and have a chance to vote for it.

My point is not that the wrong daffodils or irises, etc., win awards; merely that any garden flower can be so strongly affected by weather or other conditions that it will be unrecognizably better or worse than usual. The loving gardener soon gets used to this, and quite enjoys it. To have an old, somewhat neglected variety suddenly take fire and become a raving beauty for a season is always gratifying. Another related phenomenon occurs when the gardener has grown a certain rose or iris or daffodil for a number of years and almost unconsciously fails to give it the best treatment. This happens most often with irises, which grow lustily and increase rapidly and require a good bit of attention to dividing, replanting in really good soil and so on. With indifferent treatment even the most magnificent iris will look like nothing much, so the iris gardener, seeing brand new varieties grown to perfection with every kind of pampering, naturally thinks they are great improvements on his old ones.

If, however, a new bed is made and all the irises in it are given the same flawless treatment, it can be a true revelation how much better some old kinds are than we think they are. As in my 'Purissima' 25 years ago. It is foolish to judge any variety if it is not grown to perfection. And even when it is, there will be surprises that are interesting and amazing even when not altogether delightful.