Plant Tulip Bulbs Deep

By Dr. Francis Gouin

In New Hampshire where I grew up, tulips were a perennial crop. A single planting would last many years, producing large, beautiful flowers year after year. Here in Southern Maryland, tulips are generally grown as an annual crop.
Tulips originated in the Mediterranean region, but the bulbs are grown in the Netherlands and in northern states such as Michigan where there are long cool springs. The cool springs allow the foliage to replenish the metabolites and grow the large bulbs that produce large flowers.

Divide hostas and day lillies

Now that day lilies and hostas have finished blooming, it is time to divide them and share the plants with friends and neighbors. When day lilies become too crowded, the center of the plantings starts to die out. Avoid this fate by digging and dividing the plants, spacing the new plantings eight to 10 inches apart. Before transplanting, rejuvenate that soil by adding a layer of compost an inch or two thick and one cup of limestone per 10 square feet. This will give your new divisions a good healthy start.

   The amount of oxygen in the soil determines whether the bulb will increase in size or produce bulblets, also known as daughter bulbs. Growers plant the mother bulb two to three inches deep for the mother bulb to produce many daughter bulbs. To produce bulbs for sale, growers plant the daughter bulbs at least six inches deep to increase in size instead of producing a new generation of daughter bulbs. The deeper bulbs are planted in the soil, the lower the amount of oxygen present and the cooler the soil. These conditions force the tulip bulb to grow larger and be less likely to produce daughter bulbs.
   We Southern Marylanders can take advantage of this knowledge by planting our bulbs deeper than six inches. Our cool spring days are short in number, and our soils warm rapidly. By planting the top of the bulbs eight inches below the surface of the soil, we expose them to a limited supply of oxygen and soil that remains cool longer.
   Always plant tulips in well-drained soil. Dig the planting hole at least a foot deep and a foot in diameter. Place a hefty shovel-full of compost in the bottom of the hole and incorporate into the soil. The compost in the bottom will raise the level of the bulb so that the top will be approximately eight inches below the surface. It will also provide all of the nutrient needs of the bulbs.
   In a hole this big, you have room for eight to 10 bulbs. Place the bulbs with their flat side against the wall of the hole to get a bigger display of foliage. Blend the soil excavated from the hole with equal amounts of compost and cover the bulbs to the natural grade. The compost that is blended with the existing soil will provide all of the nutrient needs for the next five to seven years.
   Bulbs planted deep with lots of compost should produce large flowers for at least five years.
   Do not place sand under the bulbs at planting time. Bulb growers use sand to facilitate cleaning bulbs prior to shipping them. Interstate and international transportation of bulbs requires that the bulbs be clean of all soil.