Question: I'm interested in growing white asparagus, but I can't find any white varieties in any of the catalogs I get in the mail. I even checked with a few local nurseries, but came up empty. Can you please tell me where I can find white asparagus plants for my garden?
Answer: It won't be long before the asparagus spears start poking out of the soil here in Western Pennsylvania, so the timing of your question is perfect.
The reason you haven't been able to find white asparagus plants is because there are no white varieties. Instead, white asparagus is “regular” asparagus that has not been exposed to light.
White asparagus is created by blocking all light from reaching the growing spears using a technique known as blanching. By keeping them in the dark, the chlorophyll pigment in the spears does not exhibit any green coloration. Instead, the spears emerge a creamy yellow.
For those who have not tasted white asparagus, the delicate, nutty flavor is coveted by many cooks and the spears bring a premium price at market.
Because they're only available for a few weeks each spring, white asparagus is a true specialty crop.
But, despite its hefty price, white asparagus is actually pretty easy to grow, especially if you already have an asparagus patch. If you don't have an asparagus patch, start by planting any of the varieties you find in a catalog or at the nursery.
Once the plants are well-established, usually two or three years after planting, use one of the following techniques to blanch your asparagus.
Technique 1: When the very tip of the first few spears start to emerge in the spring, invert a solid, dark-colored plastic tub over the plants. Make sure no light reaches the plants as even the smallest amount of sunlight will cause the spears to green up. Leave the tub in place and check underneath it every night, cutting off any spears that have reached six to eight inches in length.
Technique 2: As soon as the spears start to poke from the soil, mound six inches of soil up over them to block out the light. Some gardeners build a frame out of wood planks, lay it over the entire bed, and then fill the frame with six inches of soil. When the tip of the spears eventually begin to poke out of this extra soil layer, dig down to their base and harvest the blanched spears.
Technique 3: For small asparagus patches, cover the planting bed with wire hoops and then place light-blocking fabric over them. Heavy, dark-colored blankets will work, but make sure they're fully supported by the wire hoops so they don't inhibit the growth of the spears.
Plants that are 3 years old should be harvested for about three to four weeks. Older asparagus plants can be harvested for six to eight weeks after the first spears emerge in the spring. After the harvest period ends, remove any extra soil or other light-blocking materials and allow the spears to grow into ferns. These ferns will grow throughout the season, and the energy they produce will go on to support next year's production.
Horticulturist Jessica Walliser co-hosts “The Organic Gardeners” at 7 a.m. Sundays on KDKA Radio with Doug Oster. She is the author of several gardening books, including “Attracting Beneficial Bugs to Your Garden: A Natural Approach to Pest Control” and “Good Bug, Bad Bug.” Her website is jessicawalliser.com.
Send your gardening or landscaping questions to tribliving@tribweb.com or The Good Earth, 622 Cabin Hill Drive, Greensburg, PA 15601.
