There may be no seeds to harvest. You have to let plants mature and set seed before you can harvest seeds in the fall.
- If you've been pinching back blooms for leaf production in herbs and some vegetables, you may have inadvertently foiled your propagation efforts.
- If you're a dedicated pruner, you may have trimmed away seed heads thinking they were somewhat unsightly.
- You may have consumed precious seeds with those delicious veggies or berries you've been growing and eating all season.
You can't harvest seeds that aren't there. A good rule of thumb is to leave at least some of your plant specimens alone from mid-summer onward with the idea that they will provide seed stock only.
Another consideration is that some hybrids either will not set seed at all, or their seeds won't be viable. There's not much you can do about that but purchase new seed year after year or use other propagation methods where applicable. Most sources will specify exactly what you're getting when buying a new plant or seed variety so you can make an informed decision.
Seeds can look very un-seed like. If you think most seeds look like the sesame seeds on your burger bun of choice, guess again. Seeds can look like flower petals, like bitty curled up bugs and like chaff, dander and other unlikely things. Sure, many seeds look like what they are, but it pays to double check before make an assumption. Seeds can employ clever camouflage techniques to hide their bounty from hungry birds and other critters. Don't be fooled.
There are a couple of reliable sources you can use to find pictures of specific plant seeds, but no source I've found is exhaustive. First, I like to perform a Google search on the plant's common name plus the term "seed picture." Here's an example: Passionflower Seed Search
|Herb and vegetable seeds|
You can also take a look at the plant profile here on my blog or perform an advanced search for sites with the extension .edu (education). This will generally produce a list of university articles about the plant you're looking for, often with life cycle photos.
Seeds may need pre-processing. Plant seeds are products of their respective environments and may need a little extra handling. Tomato seeds, for instance, typically need to "ferment" in their natural juices for a few days before drying. Without this treatment, germination rates plummet. Cold climate seeds may need freezing conditions as part of their life cycle, too. (Exposing seeds to the cold is sometimes referred to as stratifying or pre-chilling.) Seed catalogs and seed packets may include instructions regarding special handling measures. Take the time to check.
Some seeds don't last long. Where some seeds will stay viable for years, others will only last a few months and are best replanted in the garden right away. Explore the options on a case by case basis. I put together a longevity list for common herbs a while back. You'll find it here: Herb Seed Longevity List. There are probably similar lists online for vegetable and flower seeds. Before you invest a lot of time, recognize which seeds are worth the effort.
In my next post, we'll talk about some practical ways to gather, sort and store herb seeds. Have a great weekend.
HerbandVegSeed_Wiki.jpg By Rickproser (Own work) [CC-BY-SA-3.0 (http://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons http://upload.wikimedia.org/wikipedia/commons/5/53/Seed_variety.jpg http://commons.wikimedia.org/wiki/File%3ASeed_variety.jpg
CalendulaSeed_Wiki.jpg By Amada44 (Own work) [GFDL (http://www.gnu.org/copyleft/fdl.html) or CC-BY-3.0 (http://creativecommons.org/licenses/by/3.0)], via Wikimedia Commons http://upload.wikimedia.org/wikipedia/commons/d/d2/Calendula_seeds.jpg http://commons.wikimedia.org/wiki/File%3ACalendula_seeds.jpg