It’s that time of year! Having learned a lot over the past few years about harvesting and sowing seeds, this post shares the techniques I have been most successful with. The wildflower (AKA butterfly) garden created at our local hospice relied heavily (over 90 percent) on seeds. Some were purchased, many donated, and others collected or harvested by myself from my own and clients’ gardens.
Harvesting Seeds Requires Patience
The most important requirement for optimal seed harvesting success is patience, something I don’t have loads of. The seed heads have to be dried out, some actually fluffy (like dandelions) to be effective. Although I am loving this amazingly warm fall weather, seed heads are late to reach this stage this year due to the lack of miserable (cold, frosty) weather.
If you are impatient and do collect your seed heads before the seeds come away easily from the calyxes (the part of the flower head that holds the seeds together), dry them out in a warm spot, in a single layer.
Then, when they reach that fall apart stage, store them in a paper bag. Don’t use plastic bags as they hold moisture in causing your seed heads to get moldy. The faster the seeds dry out the better.
Use Brown Paper Bags to Harvest and Store Seeds
I find the best (and most cost-effective) way to collect seeds is to use brown paper bags. I use the kind we used to pack our lunches in before lunch boxes were a thing. You can still buy them in grocery stores, so someone must still use them for lunches. You could also use the brown bags given out at LCBOs, they would work just as well. For those of you not living in Ontario, they are our government-run liquor stores.
Simply hold the bag under the seed head and cut the stem just below the seed head so it falls into the bag. I use a separate (labeled) bag for each type of seed head but that’s because I collect tons of seeds. If you are collecting fewer seeds of a greater variety for a blended, random wildflower garden, store them all in the same bag.
I add a strip of heavy-duty tape (book binding tape works well) to the bottom of each bag so the seeds don’t escape through the cracks in the bags.
Seed Sowing Techniques
I have discussed my sowing successes and failures in previous posts. The easiest method (that I tried) was the outdoor winter trick using clear plastic clamshell (from grocery stores) containers. If you try this, be sure to leave your containers in a partly sunny (not full sun or full shade) location outdoors for best results.
The plastic cup method in late spring also worked well, especially to fill in bare spots. It too was easy and inexpensive.
Both the clear plastic clamshell containers (winter) and cups (spring) act like mini-greenhouses, holding the moisture in and collecting the warmth of the sun. For obvious reasons, the plastic used must be clear (not frosted, no stickers/writing etc).
Unfortunately, I have still not had much luck or success with sowing seeds indoors for spring transplanting. That technique seems to need lots of patience too. Perhaps that’s my problem. I manage to get the seedlings to a few inches tall then they fizzle out.
Before you pick one of the methods mentioned over the other, research whether or not your seeds require a cold stratification stage to ensure success. Most perennial seeds have a tough exterior shell requiring this cold step, while most annuals do not. The clamshell method includes this stage while the cup method does not.
I’ve learned to keep a journal of sorts with notes on my experiments with seeds. That way next winter I will remember which method I had the most success with and avoid making the same mistakes over and over.
I’d love to hear from anyone that has experimented with seed harvesting and sowing, both failures and successes. It is definitely a learning curve!