ANOTHER YEAR has come and gone without the blue dawn flower (Pharbitis learii or Ipomea learii ) yet it is worth sitting down and saying, "In the summer of 1980, I am going to have it."

It is a morning glory, climbing about like the annual "Heavenly Blue." Now the annual morning glories are beautiful, but P. learri is more beautiful still.

It is a perennial from South America, and none too hardy if plopped out in the middle of a field. But on a wooden trellis out from a sheltered wall, and given a mulch of hay or honeysuckle in November, it may be expected to settle in.

The first time I ever grew it I was aghast to see its leaves chewed up by little beetles slightly larger than lady bugs, only covered with a brilliant metallic gold irridescence.

It was hard to believe they were not made of solid gold. I never could bring myself to kill them, and the vine did well enough with a good many chewed-up leaves; but I never had the beautiful bugs after the first year, in any quantity.

Assuming, however, that most gardeners want the vine for flowers rather than the lovely beetles on the leaves, let me say they are shaped much like other morning glories, the bud possibly longer and the clusters larger. Stems of maybe 5 or 6 inches grow out from the main stalk and these are tipped with clusters of flower buds. Sometimes several will open the same day, so you have a little bouquet of morning glories on each stem.

The color is piercing blue, such as you see in some gentians, and "electric" is not a bad way to describe it. Like many of the most gorgeous blues, there is a strong undertone of red in it. You think the color is near spectrum blue; but when the flower fades (which it does about noon), the flower turns magenta, and you conclude the red, though unseen, accounts for some of the flower's brilliance.

I had a strange friend, an editor, who once roller skated across the state of Texas for no particular reason. I mention it only to suggest he had strong and unorthodox notions about things. And he asked me to name a flowering vine for the south side of his undistinguished red-brick house in a new subdivision.

He did not think he would like the morning glory, but finally I bought one and gave it to him. As I foresaw, he went quite to pieces when it bloomed, and for years bored everybody by singing the praises of P. learii. Books sometimes say the vine does not seed, but it does when it is happy.

When people had conservatories attached to the house, this vine was commonly seen trained up on wires, and it flowered most of the year. Outdoors it starts blooming in July and goes on till frost, but it depends on the individual plant's vigor. In any case it blooms for some weeks.

As you might suppose, it blooms before most people are awake, and begins to fade magenta once the hot sun is strong on it.

I do not know a source for this vine now, but undoubtedly a search of greenhouses would turn it up. It should be planted outdoors in May, not before, and given good soil with plenty of leaf mold and ultimately some rotted manure and a great deal of water. The idea, its first year, is to make it grow as vigorously as possible, so its chances of weathering the first winter are better.

Another vine I used to grow (only this one I still have) is the hybrid trumpet vine called "Mme. Galen." The plain wild trumpet vine that you see over pasture fences and occasionally tackling a red cedar, is Campsis radicans. We take it for granted and few gardeners do more than chop it down if they encounter it, yet it can be one of the most gorgeous of climbers, with its healthy deep green leaves of many leaflets, and its cantaloupe-sized clusters of orange-red trumpets 2 to 4 inches long.

Ants, by the way, are tremendous fanciers of all trumpet vines.

Now "Mme. Galen" is much like the plaint wild trumpet vine except its clusters are larger, the individual trumpets twice as large, and the color is a soft apricot-red.

Ten years ago I dug up a piece of the Madame to bring up here from my former garden, and I cannot say what got into her, since she sulked.

Without going into the morbid details, she neither died nor flourished, but sat there making a few feet of growth but not blooming.

Of course she loves full sun, and I grow her in a lot of shade. Also she likes fence wire to climb up and I require her to use her little holdfast rootlets (like ivy) to hold on to the brick wall.

This summer she has flowered very well indeed, and I hope we are now friends again, as we were in the old days.

I bought mine from Wayside Gardens, which now is located at Hodges, S.C. 29695.

Let me mention a slight problem or two:

Madame likes to grow straight up; and when she reaches the eaves or the roof, she can pry off gutters, lift slates and I suppose destroy the house if left alone.

All it takes is one whack with the hedge shears in March to keep her lowdown, and this inspires her to branch out more.

Her favorite activity is to send a little shoot out to the side behind the downspout from the glutters. This shoot is no larger than a clotheshanger ware, and the gardener pays no attention. In remarkably short time (I suppose it takes three years, but time goes rapidly), the gardener notices the downspout seems to be coming loose. This vine's stem has enlarged and pulled the downspout out from the wall.

Those iron clamps that are supposed to keep the pipe attached are as fluffy silk ribbons when the vine gets going. She also likes to twine around any exterior wires (like those wretched little wires the phone company likes to run from the main poles into the alley) and, in due time, will pull them down.

Needless to say, Madame ought not be allowed to grow over any delicate shrub or small tree. She could do in a dogwood in two years.

Hummingbirds are fond of the flowers, but hummingbirds are often slow to discover them. We have bumblebees almost as large as hummingbirds, and they too think highly of this vine (as indeed they admire every flower I have ever grown) and so do wasps.

Sometimes you see arbors of plain redwood or cedar on the sunny side of a house, and the trumpet vines are ideally happy in such places, though some gardeners may be uneasy at the number of bees and wasps that show up, along with the ants.

It is startling that gardeners learn quickly about traffic noise - we used to live at Chevy Chase Circle, which is ghastly in its noise - and also learn to expect the toaster, vacuum cleaner, ice box, automobile, porch columns, etc., etc., to be mixed blessings.One soon enough learns to entertain a procession of plumbers, painters, electricians, carpenters and assorted magicians to tend to all the things that need tending to. But the same person in the garden is surprised to learn Madame pulls down shingles and gutters and is host to wasps and ants; and yet the truth is that the natural world, as well as the unnatural, falls short of perfection.

A trim and pretty bride who moved into a new house told me she had thought all climbing roses bloomed steadily all summer, and was surprised when I told her none of them did.

Some climbing roses send forth moderate little flushes of bloom after their main season in May or June, but she thought they would be masses of color right through the summer.

She thinks that because writers of rose catalogues, often born liars, seem to say the climbers positively blind you with their color from frost to frost.

All things considered - wasps, ants, downspouts - I find the trumpet vines lovely and worth growing; but I have no illusion that they, or any other plant, are total joys at all seasons.

My akebia, to end on a triumphant note, is full of fruit four inches long, like fat sausages. Soon they will turn violet and burst open to display the seeds. They are not good for anything I know of and are not especially lovely; indeed, they are a bit gross, but there they are and like most gardeners I rather like to see them. CAPTION: Illustrations 1 and 2, From "Easter North America's Wildflowers" by Louis C. Linn/E.P. Dutton, New York.