Which bulb to buy? See what you get

Sunset, Oct, 1987

Which bulb to buy? See what you get

Shopping for bulbs seems like a simple task: you look at pretty pictures above nursery bins or in catalogs and select the kinds you want. But if you shop around, you may discover that bulbs--and the flowers they produce--aren't always of the same size or quality.

In the markets, bulbs are separated into different grades, much like eggs. The difference is that you usually know what grade you're getting when you buy an egg. With bulbs, nurseries and catalogs don't usually list the grades; even if they do, those grades may not mean to you.

Here, we show you how four types of bulbs are graded, and how those grades perform. This way, you can get a good idea of what you might get next spring from the bulbs you buy this fall.

How bulb size affects flower production

Depending on their shape and where they are grown, bulbs are graded in either inches, centimeters, or by how many fit into a standard-size container. Most types are sorted out into three or four different sizes. Occasionally, a substandard bulb, called a cull, finds its way into the market.

Last year we bought various grades of daffodil, ranunculus, freesia, and Dutch iris bulbs from full-service nurseries, discount garden centers, and a range of catalogs. Then we grew them in Sunset's test garden to find out how they'd perform.

We found that plant production is as variable as bulb size. In all cases, the smallest bulbs, which have less food in reserve than larger bulbs, produced significantly fewer flowers and leaves, and had weaker stems. (They'll also be less likely to bloom next year.) Small daffodil and Dutch iris bulbs produced smaller flowers.

How to choose a good-size bulb

Unless you have bulbs of different sizes to compare, it's difficult to know what a good-size bulb looks like. Use these pictures as guidelines when shopping (the daffodil bulbs shown above are 1/2 size; the three types on page 96 are shown actual size). Also, ask questions. Nurseries should be able to tell you what grades they carry. When possible, avoid prepackaged bulbs; they tend to be smaller. Choose heavy, firm, unsprouted bulbs without soft spots or large scars.

If you're planning to buy bulbs by mail, see guidelines on page 96.

Daffodils. A common misconception is that these bulbs are sized and priced according to how many "noses' they have (the point where the foliage and flowers emerge). Some varieties tend to produce more noses than others, so a double- or triple-nose bulb doesn't necessarily mean it is bigger. Instead, daffodil bulbs are graded by circumference or by the number that fit into a standard-size container.

Keep in mind that the largest bulbs of one variety may be smaller than those of another. Trumpet, large-cupped, short-cupped, and double daffodils produce larger bulbs than species and miniatures. Also, large bulbs on some varieties tend to split more than others, though this doesn't influence flower production.

Freesias. Circumference is the key measurement in freesia bulbs, since fat bulbs produce stronger stems and more flowers. (Longer bulbs aren't necessarily better.)

Ranunculus. Choose large, plump roots; avoid tiny, brittle ones. Ranunculus are started from seed, so there's a lot of variation between individual plants. Leaves of some, for example, may look like celery leaves; others will be more fern-like.

Dutch iris. These bulbs fit into two categories: the large blue types, such as "Blue Ribbon' and "Ideal', and the rest of the colors, such as the purples and yellows. The large blue types (including one white iris called "White Wedgwood') produce larger bulbs. The other colors are smaller; look for bulbs at least 8 centimeters (about 3 inches) in circumference.

Nursery versus mail-order shopping

Most full-service nurseries sell high-quality, good-size bulbs, although they aren't necessarily the largest ones available. Bulb prices and sizes at these nurseries are fairly consistent--both run a little higher than at high-volume nurseries.

If you buy from a discount garden center, choose your bulbs carefully. Prices are often low, but you're much more likely to get small or prepackaged bulbs.

Mail-order catalogs tend to offer the greatest selection of unusual varieties. Some sources sell consistently good bulbs; others can be unpredictable. If growers have had a good year, discount mail-order sources may sell large, high-quality bulbs at good prices. But in a bad year when costs are higher, many of them send smaller bulbs instead of raising the price and sending larger ones. Make sure the sources guarantee their products.

In general, watch out for catalogs that don't mention bulb grades ("top quality' doesn't always mean a good-size bulb). Call and ask for grades, if they aren't listed. Be wary of suppliers that barrage you with mailers offering cheap prices.

Cost may be another drawback to shopping by mail. In general, expect to pay more than you would for comparable bulbs from a nursery. Also, since most large mail-order sources are located in the East, shipping can be expensive; some tack on 15 or 20 percent. On the other hand, small, local mail-order sources may offer some of the best bulbs at good prices without adding steep shipping charges.