This is my first year growing parsnips. I was able to get the seeds to germinate in only 11 days using my shade disc technique (see 11-Day Parsnips). That was downright encouraging. The picture above shows my parsnip bed in early June.
You'll notice that I followed the same planting scheme as shown in my Four-Day Carrots video, but I'm growing a single parsnip in each space, not three. The bed is 30" wide and the planting holes (in the plastic) are 6" apart in the rows.
I know that parsnips can be grown closer together, but I wanted to give my first-ever crop of parsnips lots of room. I tend to give plants more room to grow after reading Steve Solomon's, Gardening When It Counts(my favorite gardening book). Steve writes in the book that when he started spacing his plantings farther apart, he got better results.
A lot of people have been critical of my first Four-Day Carrots video because of my wide plant spacing. They assert that I'm wasting space, and that they can grow a lot more carrots in a similar sized garden bed. While it is true that you can grow more quantity by spacing plants closer together, you don't necessarily get more quality. The proof of this is in Four-Day Carrots, Part 3, where you get to see me harvesting some carrots. Close spacing does not yield carrots of the size and beauty that you can see in that video (and they tasted good too!).
The more I use black plastic in my garden, the more I like it. It retains moisture and saves me a LOT of time that I would spend cultivating to keep the weeds from taking over. It translates to greater satisfaction and a better crop. The fact is, everything I've grown using a plastic mulch has grown better than if I grew in bare garden ground.
Some people worry about toxins leaching out of the plastic. I suspect that some toxic material may, indeed, leach out, but I'd bet it is very minimal. And the benefits of eating the wholesome, homegrown food surely outweigh any minuscule toxic leaching from the plastic. That's my opinion at this point.
I do, however, like the idea of using ramial wood chips as a mulch. Part of the reason I like the idea is that I have a lot of scrubby "weed' trees less than 3" in diameter growing along the edges of my woodland. I want to harvest this invasive undergrowth and put it to good use. So, at some point I will be buying a wood chipper.
But I doubt that I'll be harvesting enough ramial chips to cover my whole garden (mulching around my apple trees will be the first application). So black plastic will have its place in my home garden for a long time to come.