Ordering asparagus seed for future field establishment – how many seeds should you purchase?
A little arithmetic can help you estimate the amount of asparagus seed necessary to meet future planting goals.
December 30, 2013 - Author: Ben Werling, Michigan State University Extension
Planting new acreage of commercial asparagus is a long-term investment. Considering a new planting may last 15 years, it is important to make decisions prior to planting that increase the odds of your production fields having 15 years of at or above average yields. Many of these decisions need to be made 1.5 to 2 years ahead of time. For example, growers are currently securing orders of asparagus seed to produce crowns to be planted in 2015. This seed will be planted in spring of 2014 and grown into crowns, or an asparagus root, either by the grower themselves or a specialized crown grower. These crowns will then be harvested in the spring of 2015 and planted in production fields. Given this is a lengthy process, making sure you order enough seeds to produce the crowns you need is important.
To determine how much seed to order, you’ll need a few pieces of information. First, determine your planting density goals. Michigan State University Extension research from the 1990s showed that planting 13,000-15,000 crowns per acre increased yields over lower planting densities. The next piece of information you’ll need is percent germination for the seed lot you will be buying. Germination rates can be obtained from your seed dealer. Percent germination rates of 90-95 percent are typical for high quality, hybrid asparagus seed.
Next, be aware that – just like for all vegetable transplants or seedlings – for reasons beyond anyone’s control, not all seeds that germinate will produce plants that survive and grow. Using a conservative estimate of the percentage of seeds that will produce a healthy crown can help ensure you end up with a few extra, and not too few, crowns at planting time. Experience in West Michigan suggests that being conservative and estimating that 85 percent of germinating seed will produce a viable plant will help ensure you do not come up short. You can use another estimate based on your experience and how much you are willing to invest to reduce the risk of not having enough crowns for your planting goals.
Once you obtain this information, divide percent germination and percent crowns producing surviving plants by 100 to get proportions. Then, plug these numbers into the illustrative example below to determine how much seed per acre to buy to meet your goals. You will need to use your own numbers based on your specific situation and risk tolerance.
An example of how to estimate the amount of seed needed per acre to meet your planting goals, using the formula:
Seed/acre to buy = Planting density in crowns/acre ÷ (proportion germ x proportion of germinated seed producing viable plants)
Item: Example of values
Goal for planting density: 14,000 crowns/acre
Percent germination of seed: 90 %
Percent of germinating seeds producing viable plants: 85%
Amount of seed to buy per acre to be planted: 14,000 ÷ (0.90 x 0.85) = 18,300 seeds/acre
Multiply this number by the number of acres you aim to plant to get your total seed needs. Then, buy the number of seed lots that will get you this amount. If you planned to plant 10 acres with crowns in 2015, then in the above example you would purchase 183,000 seeds to be planted in crown beds spring of 2014.
To learn more about commercial asparagus production and the latest research, attend the 2014 Oceana Asparagus Day held the second week of March in Oceana County. Contact the Oceana County MSU Extension office at 231-873-2129 for more details.