Most microgreens take between 7-14 days to reach maturity, after which they are ready for harvesting. You can either harvest them just after their seed leaves or cotyledons appear or wait for them to put on a second set of leaves, known as true leaves. If the microgreens continue to grow beyond this, your crop will start to show signs of stress such as yellowing or become "leggy" (tall and unhealthy). This is because of the dense environment in which the microgreens are growing. If the microgreens are replanted in a less dense environment, they will grow into the full-size herb/vegetable.
A Right Time To Harvest?
The short answer is yes. In Singapore, where our climate is usually hot and humid, the best times to harvest your microgreens is in the mornings or evenings. Cutting or harvesting your microgreens while they have been in the sun for a few hours or even in the shade on a hot, humid day will result in wilted greens. The important thing to remember is to keep your greens cool. Harvesting your microgreens at the correct time will keep them looking fresh.
For the home grower, a pair of sharp scissors is the best and easiest tool to harvest your greens. Hold a section of the microgreens loosely with one hand and with your other hand, place your scissors about 1 cm above the potting mix, and snip your greens. Some microgreens grow taller then others so make sure you adjust where you snip accordingly. The idea is to not snip close to your potting mix but to not waste the harvest by cutting your green too close to the leaves.
Growing your own microgreens allows you to harvest your greens whenever you need to and eat them within minutes. This gives you the freshest, tastiest, and most nutritious salad available right from your own home.
Washing Your Greens
There are many schools of thought on this. Some say watering or rinsing is necessary, some say to do it if you want and others say to skip this step (especially if you have been diligent in your watering i.e. watering your microgreens only from the bottom or the side). Personally, I do give my microgreens a quick rinse just before eating them, only to ensure that I don't get any of the husks or seed covers on my plate.
Will I Get More Then One Harvest?
There is something called delayed germination when growing microgreens. Some varieties of microgreens will have a second wave of late bloomers: when seeds that didn't get germinated in the first crop, finally start to grow. You might find this happening in varieties like Arugula or Rocket, Basil, Beets, Spinach, Sunflower, and Peas. Sunflower and Pea seeds are known to germinate more then twice. In general, the larger the size of the seeds, the greater the yield of its second wave. However, it is important to note that after the first crop, the second crop will be meagre.