Thinking about a fresh asparagus dish and rhubarb pie makes me hungry.
These are two early spring perennial vegetable crops, and they take a couple of years to become established and ready for harvest. Instructions for the easy planting and care of asparagus and rhubarb are described below.
The best location for asparagus and rhubarb beds is where they will be undisturbed for many years. An asparagus bed may last for 20 years. Along the edge of the garden is ideal. A well-drained site in full sun is needed.
Test the soil through your local Cooperative Extension Service to determine if lime is required and the amount of phosphorus and potassium needed before planting.
A recommendation indicating the amount and type of fertilizer to apply is provided. By testing the soil, you may find additional lime or nutrients are not needed, thus saving money.
For asparagus, the preferred pH range is 6.5 to 6.8. It does not tolerate acidic soils. Rhubarb tolerates a more acidic soil.
To prepare the soil for planting in early spring, incorporate organic matter such as well-rotted manure or compost into the soil to a depth of 8 to 12 inches. Organic matter improves the soil’s physical condition and makes a better growing environment.
For asparagus, starting with one-year-old crowns instead of seeds is recommended. Two- or three-year-old plants are sometimes available, but they may have been overcrowded at the nursery and are more susceptible to damage when transplanted.
The asparagus plant crown is a combination of buds, fleshy and fibrous roots, and rhizomes, which are underground stems with buds. The fleshy roots store food reserves that help develop tender shoots the next spring.
Dormant asparagus crowns are planted in a trench 12 to 15 inches wide and 6 to 8 inches deep in March to early April. Plant at the shallower depth if the soil is heavy. Space plants 15 to 18 inches apart within the row and 30 inches between rows.
To plant a crown, make sure the growing point, which looks like a small stem with a point on the end, is facing upward. Place the bottom of the crown on a small amount of soil in the trench making sure it is higher than the roots. Spread the roots out and cover the crown with 2 to 3 inches of soil.
Firm the soil gently over the crown. As shoots begin to grow, continue to put soil around and over the crown. Repeat this procedure as the plant grows until the trench is filled.
Mulching around the asparagus plants with 3 inches of mulch, such as weed-free straw, will help control weeds. The mulch keeps the soil cool and delays the emergence of spears in the spring to avoid late spring frosts.
Asparagus shoots or spears are not harvested the first year after crowns are planted. Shoots are left to supply food to the root system in order to increase the size of the root system and to store food for the next growing season.
The second year after planting, limit the harvests to three to four weeks. Then let the shoots grow. The third year after planting, harvests can continue for eight to ten weeks.
The harvest may end earlier if numerous spears, pencil-sized or smaller, are produced. Allow the shoots to grow all summer to transfer food to the roots.
When harvesting asparagus spears, break them off at soil-level instead of cutting below the soil surface. Cutting can easily injure the crown buds which produce the next spears.
If you use a knife, be careful. Morning is the best time to harvest asparagus spears because they will snap more easily. The spears should be harvested daily when they are 5 to 7 inches tall. They should be used or refrigerated immediately to help keep their quality.
Stop harvesting asparagus when three-fourths of the spears are the diameter of a pencil.
These should be left to produce and transfer food to the roots during the summer.
The tops should be removed in the fall after they have died from a killing frost.
Removing the tops helps decrease potential disease problems.
Rhubarb is started by planting pieces of the storage root cut from the crown which contains a bud. Start with disease-free pieces to avoid a disease called crown rot.
Rhubarb crown pieces can be planted 3 feet apart within the row in March to early April.
Allow for 4 to 5 feet between rows. Soil should be placed 2 to 3 inches on top of the crown. Soon after the ground is frozen, cover the plants with straw. In early spring, rake it off so that new growth can start.
Rhubarb can be harvested for a short period during the second year after planting. The third growing season and thereafter, a full harvest of eight to ten weeks, starting in the spring, can take place.
Pull stalks from the base instead of cutting them. Cut off the leaves and use only the stalks. The leaves should not be eaten due to a large amount of oxalic acid contained in them.
For more information about growing and maintaining asparagus and rhubarb, call the Daviess County Cooperative Extension Service at 270-685-8480 or email email@example.com.
Annette’s TipWhen looking to purchase asparagus, the University of Kentucky recommends the cultivars Jersey Knight, Jersey King, Jersey Supreme, Jersey Giant, and Jersey Prince because they have disease resistance against the fungus called rust.
Annette Meyer Heisdorffer is the Daviess County extension agent for horticulture. Her column runs weekly on the Home & Garden page in Lifestyle. Email her at firstname.lastname@example.org.