Parsley does it discreetly, coriander without hesitation, rhubarb is at no matter how many times you dare it not to be, and dill is just a show-off. Like it or not, plants are sexual beings and reproduction is going on in your garden in myriad ways whether or not you condone it! Permaculture (a sort of free-love garden philosophy which advocates just letting them get on with it) embraces all this promiscuity and reaps the rewards – self sown herbs and vegetables, and a garden that never needs resowing. I, on the other hand, prefer a little more control on the situation because plants, left to go to seed, can be a pain.
Brassicas tend to sleep with anyone and the resulting cross-pollination means you seldom know what off-spring they'll produce. Then there's the habit seeding plants have of dropping potential babies all over paths where they become as much of a nuisance as weeds. But the real problem, I find, with letting plants go to seed where ever and when ever they want to (especially in a cooler climate) is that they just take so darned long to produce the goods. And while they're going about their business, they grow taller and taller and wider and wider, occupying far to much of my precious growing space and, very often, shading anything around them that's trying to grow.
But who doesn't want to harvest their own seed? It's so exciting to sow a garden without ever having to buy a packet of anything from a shop, and so rewarding to think you can go it alone in this world of commercialism. My answer to the problem of maintaining orderliness in the garden while allowing plants to get on with what they do best is to sow a pinch or two of various seed along the edge of my paddock spud patch. Robust spuds won't mind a little shade from a towering parsnip or carrot left to go to seed. A leek or two reaching for the sky will barely be noticed, and silver beet can spread out as much as it wants to. Nothing requires careful attention because it's not the vegetables I'm after, just their seed. After the ever-tolerant spuds have been dug, the herbs and vegetable plants stay where they are, and my reminder to collect their seed arrives the following spring (or, summer) when I head down to the paddock to put in the next lot of potatoes or dig them.
My latest harvest from the potato patch is parsnip seed. Just three plants produced a large tray of fresh brown seed which I am now drying thoroughly on a sunny window ledge in the house. I'll sprout a few just to check they are viable and, assuming they are, will indulge in some child-like playfulness by folding brown paper into little envelopes and decorating them with drawings of parsnips. I'll fill them with seed, label, date, and seal them, and give them to my garden friends as gifts. And all the while, my own vegetable patch will remain as neat as a pin. All very satisfying if only it weren't for the fact that my permaculture friends will, no doubt, suggest my controlling personality requires therapy!