How To Harvest Seeds From Your Garden, Part 1: When Are The Seeds Ready?
Clip, Snip . ..no, ugh, wait - what?
After a season of growing, watering, weeding, watching, and waiting, the time to collect your own seeds has finally come! Or has it?
Perhaps the hardest seed saving skill to learn is that of identifying WHEN seed is mature enough to collect. Cut the stocks too soon, and you have useless immature seeds that will not grow. But wait too long, and mother nature takes actions into her own hands and scatters the seeds you’ve so carefully been tending.
In this post, we are going to take a look at seed maturity across different types of vegetables so that you can time your seed collecting and gather mature viable seeds that will support your gardening habit for years to come. We will look at everything from plants with seed pods and heads, all the way through to the plants that have fleshy seed chambers that require extra steps for collecting and cleaning.
Let’s dive in.
The Basics of Seed Maturity
The task of seed saving seems quite straight forward on the surface. Simply wait for the “signs” that the seed pods or fruits are mature to over-mature, and then gather them up.
In reality, figuring out “maturity” is across different plants and varieties has some unexpected challenges.
Signs of maturity for plants with pods typically include things like pods shifting from green to yellow to brown. Also seed pods tend to go from small and thin, to wide, rounded, and showing bumps where seeds are sitting. Most of the brassicas (broccoli, mustard, arugula, etc.) and many herbs have pods.
For other other plants with fleshy seed chambers, such as cucumbers, melons, tomatoes, and zucchini, “ripe enough” for seed collecting is VERY different than ripe enough to eat. These foods have to be overmature to create viable seeds. Maturity may look like being over-sized, changing color, thickening of the skin, cracking, or even the early stages of rotting.
Vegetables and fruits we commonly grow in the garden must be fully mature in order to produce seeds that are viable for seed saving. The goal is to harvest seeds that will grow into next year’s garden. That goal is different than simply having food to eat this season. Remember to check your garden journal for notes on which plants have been the best this season.
If you are new to The Naturalized Human and Successful Seed Saving 101, then it’s easy to go back into previous posts and catch up. Throughout the 2024 growing season, I’ve been rolling out the steps I take to save seeds each year.
Tools you need for seed collecting
Seed saving from the garden doesn’t take much in terms of sophisticated tools. Essentially you need something to cut the seed pods, stems or fruits off the parent plant and somewhere to put said pods, stems and fruits afterwards while you separate out the seeds. Remember to keep each plant variety separate, if you want to know exactly which seed is which next year when it is time to plant again.
The best strategy I’ve found for dry pods and seeds is to cut them into paper bags. When it comes to the fleshy veggies - I collect them up and take them into the kitchen where they can be dissected for seed extraction.
To collect up your seeds, you are going to need the following tools:
Scissors and/or hand-help pruning shears
A sharp knife
Paper bags
Marker
Large flat container for catching stray seeds
Basket if you are harvesting up fleshy vegetables for seed collecting
When Are Seeds Ready For Harvest?
Plants with Dry Seed Chambers
Let’s start with the easy ones first. Plants that produce seeds in some kind of pod or on umbels or stems are the easiest to determine maturity and the easiest to collect (even if you get it a bit wrong).
When the pods and seeds are still green (picture below, left hand side), it is generally too soon to clip them. They just don’t have enough energy to mature into viable seeds.
But if you see pods split open (picture top right) or brown umbels with just one or two seeds (picture bottom right) , then you’ve waited too long.
Half have turned color
As these seed pods turn yellow and just start to fade to brown, or when at least half of the pods or seeds are turning light brown, that is the earliest you can collect these pods and get viable seeds.
How? The best way I have found is to start at the seed pod or branch you want to harvest from, and run your hand well down the stem towards the soil. Snip the longest section of branch that will fit into your paper bag or bin. This long branch will continue to send all of its energy into the seeds and pods, allowing them to complete their maturation in your bag.
It’s important not to pack your paper bag or bin too full of stems when they are not fully mature like this. Too much moisture will trigger the entire bunch to mold and rot.