Quintet of Yellow-Petaled Springtime GreetersHere are five floral milestones that mark out that many stages of spring (as seen by this writer).

The first wild plant in the Northeast to promise winter is losing its grip is marsh marigold, also called cowslip. This plant isn’t even slightly related to garden variety marigolds; it’s in the buttercup family. Marsh marigolds are commonly found in very damp soils – even upland marshes – thus their name. They can grow up to two feet tall, with hollow branching stems.

The earliest I’ve ever seen them mature enough to be harvested and eaten was March 15. Add four weeks to that to get 2023’s edible date.

Marsh marigolds require constant moisture. Thus, their most suitable habitats are swamps, streams, wet meadows, ponds and shallow water on the edge of lakes. This plant is perennial, with flowers two inches in diameter, bright yellow to whitish. Each blossom has five to 10 petal-like sepals. Since cowslips contain the toxin glycoside protanimomin, these plants must be boiled to destroy this poison. There are several recipes for making this “sort of” vegetable edible; they all require lots of boiling. Boiled and drizzled with vinegar, cowslips taste like spinach that has been boiled and drizzled with vinegar.

The next early bloomer is buttercup. The sap of this soggy soil resident is also laced with glycoside. To a lesser extent, so are the other parts of the plant – flowers, seeds and leaves. The greatest toxin concentration is in the flowers. Drying the plant negates the poison; then cattle can safely eat it.

Although baled dry buttercup hay can be safely eaten by ruminants, its net feed value is iffy. Making buttercups into baleage or haylage is probably not a great idea, since we don’t know how well fermentation knocks out glycoside. I have personally learned the hard way that hitting buttercup with a weed-eater is very unwise, since atomized glycoside tends to paralyze lungs (or at least mine). Stepping away from the noxious mist eliminated any further health issues – as did putting away the weed eater.

The third yellow harbinger of spring is yellow rocket. The most common early source of yellow pigment in existing meadows comes from rocket, this year appearing about four weeks later than normal.

In January 2015, Penn State Extension field crops agents officially designated yellow rocket as Weed of the Month. Rocket can be winter-annual or biennial, and reproduces from seed, which can germinate in both spring and autumn. Young leaves are round or egg-shaped, poised on short stalks. Flowering stems occurring during the second year and can, when mature, exceed two feet height.

Yellow rocket, a member of the mustard family, is earliest to flower in that grouping, usually very soon after snow is gone. Lower leaves become lobed, while the stem leaves develop deeper indentations and thick green foliage. Yellow flowers are produced during spring at the upper stem, where they are grouped in clusters. Pod-like fruit is long and sharp at the tip. If not mowed, the fruiting stalk remains all summer. Yellow rocket forms a taproot, but can be removed by hand when small, which isn’t an option in meadows. Penn State agronomy agents stress that there are no effective anti-rocket pre-emergence herbicides.

Three years ago, temperatures in Central New York seemed suspended between 45º and 55º F for the last 10 days of April. A dairy farmer who had moved up from Pennsylvania a couple years earlier called me in a panic, just before daybreak one late April morning. His meadows were infested with yellow flowers, the likes of which he had never seen before. I told him that I was 99% certain that they were yellow rocket, and that mowing them would make the stand helpless for this year. (Strange that he’d never seen these weeds in an area where weed scientists were very familiar with them.)

In his textbook “Weed Control Without Poisons,” Charles Walter described the conditions which made yellow rocket feel very much at home. He wrote that the plant is a smooth-stemmed native of North America and can be found in new meadows (generally second year growth), along roadsides and in fields. Importantly, soils where this weed is found are low in calcium and very low in phosphorus. This Quaker State transplant was organic, so to rectify this phosphorus shortage (which was documented by soil test), I recommended he apply some bone meal, since monoammonium and diammonium phosphates were not allowed by organic standards.

The fourth yellow-blossoming wild plant to heed as a sign of spring is the dandelion. When grassy to mixed mostly-grass meadows turn from yellow to white fuzz, it’s time to mow these fields. Occasionally remove the grayish-white fuzzy mat from the haybine, then throw it into the swath to be chopped (or round baled), since its feed value is generous.

The fifth yellow bloomer to announce spring is wild mustard. Wild mustard will try to take over new seedings, as well as spring-planted small grain stands, but not till the last week of May (or the first week of June this year, because of the tardy onset of spring). Both yellow rocket and wild mustard are members of Brassicaceae family, essentially making them second cousins.

We see that wild mustard boasts the following first cousins (by common name): tame (yellow) mustard, all the cabbages, Brussels sprouts, broccoli, cauliflower, kale, kohlrabi, canola, collards, turnips and rutabaga. Wild mustard can be smooth stemmed, so it can be confused somewhat with yellow rocket. But wild mustard petal pigment leans toward pastel yellow.

A small taste of leaves of each smooth specimen reveals that rocket is somewhat bitter – though not toxic – and wild mustard is a little radishy. Rocket matures before mustard, but if you do save some rocket seeds, you’ll find they’re smaller than those of their second cousin maturing later.