Harvest Season At Irvine Ranch Conservancy

The team at the Irvine Ranch Conservancy (IRC) takes on a variety of roles each day, including that of a farmer! Because IRC constantly needs plant materials like seed and container plants for habitat restoration projects throughout the Irvine Ranch Natural Landmarks, the team utilizes their Native Seed Farm to grow and harvest plants and seeds. Although the harvest season at the Native Seed Farm may span the entire year, Jesse Potter, the Project Manager of Plant Materials Development at IRC, emphasizes the importance of this period while highlighting the crucial work being done by IRC.

What does “harvest season” mean for IRC? 

For IRC, harvest season is any time of the year when we are collecting seeds from our native plants. We primarily harvest plants from the Native Seed Farm, however, we do conduct wild seed collection for these plants as well. Wild harvested seed is used for both habitat restoration and starting new crops at the farm.

How does the harvesting process work?  

We process all of the seeds we harvest, whether from the farm or habitat, at our facilities at the Native Seed Farm. The process starts directly after a harvest when we start drying most seed species. We do this to prepare them for further processing, to reduce the amount of space seeds take up in storage, and to ensure we can keep them at the most optimal conditions for storage. During the process, we try to remove as much non-seed material from our harvests as possible. This is achieved by running the harvested material through processing equipment. Our equipment ranges from simple tools like mesh screens to specialized machines such as our thresher, which pulverizes material over a concave screen that is selected based on seed size and then sorts this material by weight using airflow.

What is the timeline for harvest season? 

Harvest season varies every year depending on what species we are growing at the Native Seed Farm and what we need to collect from the wild, but our collection season encompasses much of the year. We collect seeds from most annual species in spring and early summer, and most perennial species from late spring throughout the fall. However, one of our most common species, California sage brush, is harvested in the winter. 

How long can you hold onto the processed seed to use in restoration projects?

The longevity of seeds varies widely by species, however, most of our seeds can be expected to last around five years in our storage conditions without losing viability. We do know that some species have very poor seed longevity, sometimes lasting only six months or so even in refrigerated storage, so we typically try to use all of the harvests the year they are collected.

Can you quickly describe the growing process overall?

The growing process for plants at the Native Seed Farm is somewhat dependent on the species. We usually sow seeds of all our annual species directly in the ground in late fall, to ensure they receive proper germination and have as long of a growing season as possible. Because they go through their entire life cycle in one year, annual plants are always sown and harvested within one year. We plant all of our perennial species in the winter, to make use of our rainy season as well as avoid conditions like hot and dry weather that could cause stress or even kill our young plants. Our perennial species are somewhat variable, with non-woody species often producing some seeds within their first year and woody species sometimes needing a little longer to mature. We usually only keep our perennial crops for 3-5 years for a couple of reasons: As shrub-like species become woodier with age, they tend to produce fewer flowers, and therefore fewer seeds, so replanting allows us to maximize seed yield.  Replanting also allows us to refresh the genetics of the plants we are growing at the farm.

 Are there any challenges during harvest season?

The main challenge we have during harvest season is triage! There are often multiple species that are ready to harvest at a time, in addition to other work that needs to be done at the farm like weeding, bed maintenance and seed processing. Because of this, we carefully prioritize our work in order to fulfill seed needs and prevent the loss of a harvest. For example, we may prioritize the harvesting of one species over another because there is a high demand for it in comparison to the other species. One of the other challenges we face is actually wildlife! Our native animals naturally want to eat the fruits and seeds of our native plants, so we try to dry our harvests and prepare them for processing as soon as possible in order to mitigate loss.

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The Native Seed Farm and its dedicated teams have played a crucial role in the success of numerous restoration projects within the Landmarks. If you would like to show your support for IRC, you can explore upcoming public activities at Native Seed Farm on LetsGoOutside.org.

• October 4- Growing Together at the Native Seed Farm
• October 11- Growing Together at the Native Seed Farm
• October 12- Growing Together at the Native Seed Farm
• October 18- Growing Together at the Native Seed Farm