Richard Bogren, Gill, Daniel J. | 10/27/2017 2:50:51 PM
By Dan Gill
LSU AgCenter Horticulturist
(10/27/17) We’ve become accustomed to running out and buying flats or pots of blooming bedding plants to create “instant flower gardens.” This last-minute approach, however, will simply not work when using spring-flowering bulbs in the landscape. If you want beautiful beds of daffodils, tulips or Dutch irises next spring, you should think about planting them now.
Spring-flowering bulbs are those that generally bloom in our climate between February and April. You may see information dividing these bulbs into categories based on when they bloom in spring — such as very early, early, mid-season, late and very late. Choosing different types of bulbs that fall into more than one of these categories will help you achieve flowers over a longer season.
When buying bulbs, try to purchase the highest quality your budget will allow. The quality of the bulb you plant relates directly to the quality of the blooms. Selecting loose bulbs at a local garden center is like choosing produce at the supermarket. Pick the largest, plumpest bulbs that are firm with no obvious cuts, soft spots or rot. If you are ordering from a catalog, do so as soon as possible and generally choose the larger sizes.
Actually, the flowers of many bulbs are not especially long-lasting. A tulip bulb, for instance, produces one flower that lasts about seven to 10 days. Ranunculus, on the other hand, can bloom over a four-to-six-week period. Overall, though, the price you pay for color from bulbs is higher than for longer-flowering cool-season bedding plants like pansies and dianthus. If your garden budget is limited, use spring bulbs more for embellishment rather than providing the primary floral display.
Good drainage, part to full sun and moderately fertile soil are all that are needed for bulbs to do well. The average landscape bed generally provides adequate drainage, but avoid low spots that tend to stay damp. You know how wet our late winter to spring period can be. If drainage is in doubt, plant in raised beds. If you choose a spot with some shade from the afternoon sun, the flowers may last a little longer, especially if the spring weather turns warm.
It is important to plant bulbs at the proper depth. A rule of thumb is to plant bulbs at a depth equal to twice their height. This far south, we generally don’t plant bulbs quite as deep as standard recommendations. Smaller bulbs are planted about 1 or 2 inches deep while larger bulbs are planted about 5 inches deep. Dig individual holes the proper depth, or excavate the area to be planted to the recommended depth and plant all the bulbs at once.
Once the bulbs are in the ground, you can plant over them with low-growing cool-season annuals, such as alyssum, violas, lobelia or pansies. Be careful not to disturb the bulbs. The annuals cover the bare soil and provide color before, during and after the bulbs bloom. Make sure the bulbs will produce blooms taller than the annuals, and make sure the colors of the annual flowers contrast with or complement the flowers of the bulbs in a pleasant way.
Although the proper time to plant most bulbs is October and November, there are a couple of notable exceptions. Tulips and hyacinths will perform much better if they are refrigerated at least six weeks in the vegetable bin of your refrigerator prior to planting, and storing longer than six weeks is better. Store them in well-labeled paper or net bags away from apples and other fruit. Plant them in late December or early January when the soil has had a chance to get cold.
Many of the spring bulbs available locally or in catalogs will only bloom reliably for us their first year. Some of the favorites include tulip, grape hyacinth, crocus, hyacinth, ranunculus, anemone, scilla, freesia, ixia, sparaxis and ornithogalum.
The following spring bulbs tend to be reliably long-lived in Louisiana and should bloom for several years at least: Narcissus cultivars such as paperwhites, Chinese Sacred Lily, Soleil d’Or, Grand Primo, Cheerfulness, jonquils, Sweetness, Trevethian, Peeping Tom, February Gold, Thalia, Ice Wings and Petrel. Larger-flowered daffodil cultivars include Ice Follies, Unsurpassable, Carlton and Fortune. Other reliable reblooming bulbs include snowflake (Leucojum aestivum), some flowering onions (Allium neapolitanum, A. drummondii), ground orchid (Bletilla striata), amaryllis (Hippeastrum species and hybrids), Spanish bluebells (Hyacinthoides hispanica), spring star flower (Ipheion uniflorum), Dutch iris (Iris x hollandica) and Easter lily (Lilium longiflorum). More spring-flowering bulbs reliable rebloom in north Louisiana than in the southern part of the state.
To have tulips blooming in Louisiana in the spring, they need to be chilled for six weeks or more and planted in late December. LSU AgCenter file photo