Seeds in Nature

Seeds are the gateway to new life. By caring of seeds in your planting beds, you get a front row seat to witnessing nature at work. However, the entertainment is subtle. A recent trip to the the South Orange Rain Park became a great refresher at just how amazing ecology is and how everything is interconnected. Its beauty isn’t an extrovert but goes about its business out of sight. Seeds have a secret I can’t stop thinking about.

​Every autumn, there's a flurry of articles about how to sustainably manage all of the leaves dropping from the trees. One really popular notion is to put them in your flower beds as mulch. I’ve never been a huge fan of this practice because too many leaves can easily hurt the growth of perennials and grasses come spring. For one, lots of natives that go “dormant” are actually semi-evergreen like Lobelia cardinalis that have small basal leaves green and healthy through coldest months of the year. They want to see the sun as much as they can throughout the winter so too many leaves make this impossible. Pycnanthemum muticum is another semi-evergreen perennial with small leaflets near the ground. In fact, there's a long list of these semi-evergreen perennials that only "look" asleep. 

A thin layer of leaves are on the Rain Park. Just enough for the seeds underneath to get exactly what they need.

The real excitement is the relationship between autumn leaves and seeds from native plants, and at the rain park this dynamic is in full display. In late autumn, a bunch of volunteers reseeded the mounds. It was the first of, hopefully, many seedings to come. We purchased some seeds and had harvested others. We wanted multiple sources for the seed in hopes it will give us a higher genetic mix for the different plants. A larger variety of genes means healthier flowers in the long-term. 
Once the seeds are on the ground, they need to stay there. That means we aren’t going to do the normal “fall cleanup” that most outdoor spaces do. If we did, we'd just wipe all of the new seed away. This is particularly true when you use high powered leaf blowers. A garden full of dormant plants is full of life, color and textures. They express a mood unique to the season. What some think of as dead plants is actually a landscape crackling with movement and beauty. The seeds greatly benefit from letting the dormant plants stay. 

For the seed, this act of doing nothing is much bigger. Because we didn’t clean the area, a small layer of leaves are covering the park. This mat of leaves acts as protection for the seeds from things that might eat them, and a thin carpet to help hold them stay in place. All this gives the seeds a chance to survive the winter, but it also sets up the seed for success when warmer days come back. 

Native seed needs dark, warm, humid places to germinate. Humid and warm is not a description for New Jersey in January (though we are having quite a mild winter so far). However come spring, the leaves will act like a mini-shade greenhouse for all of the seeds beneath them. Anyone that’s kicked around in the leaves know that it seems like underneath is alway full of water. 
Yet before the spring comes, all of that water is doing something else too. In most places, it’s not always a frozen tundra from Dec to March. It freezes and then thaws and then freezes again and then thaws again. All of this freezing and thawing prepares the shell of the seed to crack open when the time is just right. In fact, native plants don’t want to be sowed in warm or hot weather. They like getting put into the environment in late fall when the frost is starting to be a nightly occurrence.

The soil bunches together when it freezes. Seed falls into these ridges and get covered with loose dirt when things thaw.

​Another thing interesting about native perennials is that they don’t really want to be buried deep in the dirt. They like to be pressed in the ground and maybe be a 1/4 to 1/2 inch under loose soil. This little detail seems arbitrary until notice how soil looks on a cold morning. As it freezes, the dirt bunches together making a ridge-like pattern that slightly opens the soil. These small ridges are exactly the depth the seed wants to get buried. The ridges appear as the dirt freezes and the seeds fall in. Then the dirt thaws and covers the seed w about a quarter to half inch. Nature’s magic. After the winter, the stage is set for the prefect conditions for germination and new life to pop. 
It’s knowing all of these little facts that make my visit to the rain park so exciting. You can literally see nature at work. This coming spring should be a very amazing time around in South Orange. The Rain Park will have more flowers than last year and nature will be a little more on display.