Seed Bank

The soil is a seed bank...has been ever since evolution worked out the mechanics of plant propagation by seed. Seeds remain viable for a shockingly long time when you consider it...from a year to 100 years under ideal conditions. Possibly longer viability exists but on average I believe it's about 5-25 years for flowers, vegetables and WEEDS. Factor in that plants produce enormous amounts of seed that simply get tossed into the environment as a matter of course and you start to realize why strange plants can show up out of apparently nothing as soon as the earth is turned over for the first time.
Things that came up from last years seed: Oriental poppies, regular poppies, chives, calendula, flax, Sweet William, cornflower etc. 

 A pea plant might put out 50 to 100 seeds per plant, a radish or corn 500. A single poppy plant could put out 1000s of seeds. Ferns and fungi probably 10 times those amounts- not that I deal with them in this semi-desert...I deal mostly with weeds. Before I start my garden I always do a 'first pass' of weeding...pulling out all the evident undesirables, give it a good raking and then watering. In a week more weed will have shown up that gets pulled and if I have time I will do this once again before actually planting anything. The seed bank will never be emptied so I'm just getting rid of recent arrivals. Besides not wanting weeds to take over my garden in the current year I don't want the perennials to settle in for a lifetime...dandelion, goatsbeard and alfalfa are terrible plants that put down really long taproots; if they are broken in the pulling attempt they will re-grow from the remnant piece.

This year I discovered just how much of a seed bank the compost pile can be. The compost is where I tossed out all the spent flowers and vegetables (as well as weeds) and it almost drove me crazy trying to get rid of all the flowers that were coming up EVERYWHERE...cosmos, cornflower, calendula and poppies. Normally I plant these flowers but I didn't intend to have them in the veggie rows which is where they have kept coming up...and where I had planted them last year they self seeded so profusely there wasn't room for anything else. I actually tore all the old flower beds up and treated them like weeds because I need that room for those 50 tomato plants!

Last years compost with potatoes, radishes and sunflowers growing out of it.

But back to the seed banks...I have lettuce and dill turning up all over the garden. These are coming from seeds that dropped there from the wind last year- plus my own rather sloppy seed sorting techniques as I collected vast amounts of seed to save. There are also wild roses starting to appear... I had collected a lot of wild rose last year for making jelly and tea and threw the branches into the compost bins. The problem in an arid windy climate is that the compost doesn't rot that well. It gets dry so quickly that the decomposition process that generates the heat that helps to break down the plants has a hard time starting. We have lots of sun, wind and virtually no humidity so the last stuff to go into the compost probably doesn't really even begin to rot. In some cases I can save these unplanned surprises- but in most cases they have to get tossed.

A wild rose coming up in my garden. I think I will keep it.

For this post I hunted around for some charts that could show how many years vegetable seeds can remain viable if stored in a cool, dry and dark environment. This list is averaged out over a number of sources that vary a good deal. It is safe to say that the numbers here are a general guideline ONLY. Seeds may last a lot longer if they are exceptionally well stored or of a particular variety that has greater longevity. Likewise, their source of origin must be considered: the seeds come from a discount shop that kept them on display in a hot, bright location will not keep as well as seeds collected from a person's own successful crops- particularly if an effort was made to collect only the best seeds.

(Some of these veggies are a total mystery to me!)

Brussels sprouts4Parsley 4
Cardoon4Potato Seed6
Chinese cabbage3Rutabaga4
Corn, sweet2Squash5
Cress, water5Strawberry4
Cucumbers5Swiss Chard4

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