Spring garden detective work
Ahh, springtime in the garden. Gardeners everywhere sow their seeds, transplant and divide their perennials, and watch for treasures as seedlings sprout in their beds.
Last fall my husband and I removed the sandy soil from our vegetable beds and lined them with leaves and then covered them with composted mulch and let the area lie fallow for the winter. Over those few months, many weeds sprouted as you can see in the photo where I've labeled a few of them.
A weed or not a weed? That is the gardener's question.
Yes, we sure have a lot of weeds here in Florida! The Florida Betony (Stachys floridana) is recognized by its opposing, toothed leaves and square stem, because it's in the Mint family. (See below for more on this plant.) The Chinese Tallow Tree (Sapium sebiferum), a noxious weed tree, sprouts its cute little seedlings with its heart-shaped leaves. Pull them out: all of them, for the sake of our native plants. Smooth Ragweed (Ambrosia artemisiifolia) has deeply divided leaves. They look pretty, but ragweed is said to cause 90% of the pollen-based allergies from late summer through fall. This plant was named by Linnaeus, the great plant classifier, but he must have been joking. Ambrosia means food for the gods, but this Ambrosia is not edible, nor does it provide nectar for insects. The Yellow Wood-Sorrel (Oxalis corniculata) is also called sour grass, because its oxalic acid makes it sour. Its leaves look like sorta like shamrocks and a bit like the three-leaf clover. It loves to take over any open soil.
There were also some pleasant surprises like this four-inch tall, yellow wildflower. I was confused because it looked like blue-eyed grass, but it was yellow. After some research I found that it is a blue-eyed grass (Sisyrinchium rosulatum). That's one trouble with common names. They can lead down the wrong path. Because I don't know its requirements, I transplanted these cute wildflowers to various spots on our lot to see where they do the best. (Update: This is a nonnative weed and I pull it out as soon as I see its yellow flowers. It's not easy to differentiate it from our blue-flowered native species without the flowers.)
Most of the detective work in the spring is identifying the seedlings. Whether you sow seeds in a meadow setting or in neat rows, experienced gardeners learn over many years what's a weed and what's not. Sometimes you can identify a seedling by its first leaves: also called the seed leaves or cotyledons. (Most flowers and vegetables that are grown from seed have two seed leaves and are called dicots. Grasses, irises and lilies are monocots and have one, narrow seed leaf.) Even the most practiced gardeners may need to wait for the next set of leaves: these leaves will be more typical of the plant and won't be the shape of the seed casing.
Here are some rules-of-(green) thumb:
1) If you sow seeds directly into your garden, label the rows
or areas so you know what to look for. I never trust my memory on this.
My mother use to use the seed packets stuck on sticks as labels, but since
I rarely use the whole pack of seeds, I usually
use a grease pencil on a plastic stake.
2) Whether you grow seedlings in pots, in fields or in rows, you can generally figure out which seedlings are the ones you've sown by their configuration or by their sheer numbers.
3) When we moved to Florida in 2004, I didn't know what would grow here. I've left some open soil each year and watched what sprouts. Then I compare what grows in this area to what's growing where I've planted seeds. I can more easily determine which are my desired seedlings.
4) Until you know, let it grow. One of my elderly neighbors is an avid gardener and is always working in her yard. She told me that one year she was sick and couldn't get out in her garden for several weeks, but when she did return, some shrubs that she'd never seen before were blooming. She'd been pulling them up all those years, not knowing how attractive they were.
Weed: A definition
A weed is any plant that grows where it's not wanted. Here's an example from my friend Helen Marshall: A rose in a wheat field is great plant, great flowers, not a great location. The wheat farmer, who doesn't have time for niceties, digs it up and tosses it out. A gardener would gently remove it to a more preferred location.
If you plant by the book or have a garden installed by a professional landscaper anything not in the garden intentionally is a weed. I think that attractive and hopefully native plants that present themselves, like my yellow, blue-eyed grass, but aren't on the garden plan are anything but weeds. They're gifts!
I've described some weeds above. For me, a weed is a native or nonnative species that have undesirable effects or have the potential to crowd or even eradicate native or garden plants. Early identification makes their eradication more manageable.
You know you're a gardener when you can identify plants by their roots! I've already discussed Catbriar (Smilax spp.) and Poison Ivy (Toxicodendron radicans) roots in my vines article. Last year I found a number of pure white, segmented objects looking very much like the tail end of a rattlesnake in the ground near my mulch piles. At first I thought they were insect larvae, but then I found some with roots attached.
This spring I finally figured out that the rest of the plant is Florida Betony or Rattlesnake Weed. Like all members of the Mint family (Lamiaceae), it has square stems and opposite leaves. The pinkish tubular flowers are born in whorls of six. This Florida native is so aggressive that it's treated as a noxious weed in many states.
I read that some people eat the tubers. They said that the crispness of the tubers is similar to radishes. Hmm. Feeling brave and knowing that most anything in this family is edible, I dug one up and washed it off. "They" were right. It is crisp like a radish, but sweeter and not as hot. My husband tasted it, too. Hey, we could develop this as a new crop. Maybe we could find that there are special "performance" enhancing qualities and make millions of dollars marketing an aggressive weed. Nah. I'd rather be in my garden.
I encourage you to become a garden detective. Gardens are always interesting when you pay attention; you just never know what you'll unearth.
Ginny Stibolt moved to northeastern Florida in 2004 and even though she's a botanist and lifelong gardener, Florida gardening was a shock. She started writing The Adventures of a Transplanted Gardener columns for the Times Union newspaper in Jacksonville. This is one of those columns archived here on Floridata.com for your enjoyment. Now she's written three Florida garden books published by University Press of Florida: Sustainable Gardening for Florida, 2009; Organic Methods for Vegetable Gardening in Florida with Melissa Contreras, 2013, and The Art of Maintaining a Florida Native Landscape, 2015. Check out her blog for the latest news and articles: www.GreenGardeningMatters.com