Starting seeds in the spring is always an exciting undertaking. It can be challenging too, as anyone who wants to grow a large quantity of plants knows. Because that can end up being hundreds of plants if you grow multiples of plants, including both vegetables, herbs and annual flowers. I have been experimenting with 98 cell trays. I found these work well for trialing older seeds and getting a jump on starting those seeds that need warm temperatures.
The great thing about the 98's is that you can start lots of plants in a small space. A 98 refers to the number of cells in a flat.
I set up a 3 tier wire shelf unit and suspended 16" LED lights over the flats. I made sure to get the lights very close (with in inches) of the plants. Artificial light does not have the intensity of sun light and as such needs to be very close.
This flat above, started on 2/20/19 were about this size 3/19/19. If you wonder how I keep track of the different plants in a cell flat. I make a map using A-N across the bottom and 1-7 up and down. Thus I can assign an alpha numeric note for each seedling. I put a couple of labels with N7 and A1 to use as a reference.
Starting lettuce in 72 flats also works as a way to get lettuce up and growing in a warm spot, and then transplanted to a cooler spot to grow on.
I transplanted these into window boxes and grew them on in a cold frame. Temperatures went down to just above freezing with no problems.
This close up shows:
1) Zinnia: Zinnias germinate fast and grow quickly 2) Pequin pepper: this tiny pepper like all peppers are slow to germinate and grow.
3) Lemon Gem Marigold: The sporadic germination is the result of the age of the seeds. 4) Carrots: also part of an old seed trial, with poor germination.
5) Amethyst purple Basil: These are 2017 seeds and the germination was amazingly good. Notice the distinct half circle of the first leaves (cotyledons)
6) Cracker Jack Marigolds: Also from 2017, great germination and growth.
As the seedlings grow, they get quite densely packed. This can quickly lead to problems if the plants aren't watched carefully. Particularly drying out.
1) Agastache: Being in the mint family they have a distinct wavy leaf and square stem 2) Loose Leaf lettuce and behind it Kale. 3) Genovese Basil with its distinct wide curved leaves. 4) Peppers: once they get going, peppers grow as fast as almost any plant.
Here is an example of some Echinacea trials:1) Echinacea seeds from 2017, produced surprisingly good germination. 2) Red Cabbage: These may need a bit more light as they are getting leggy and leaning. 3) It seems that Lettuce seedlings really prefer lots of room, the best growth I got was from single seeds that sprouted and grew alone.
I frequently plant a "mini" row of one seed variety. In a 98 that equals 7 "cells" to a row. In that situation, I'll write one label with and arrow pointing down. On the left you can see I planted Marigold 'Brocade Mix', I put in a sideways arrow and a number (21) to indicate that there are 3 rows of 7, for a total of 21.
Here are Marigold, Pepper and Tomato seedlings. The Marigold and Tomato plants have well developed roots. These plants are about ready to be transplanted. The pepper plant has hardly any roots evident, and so could be grown on longer in the 72 cells. Multiple plants in one cell can be teased apart by dipping them in water to loosen the roots.
As close up of 1) Basil seedlings, that have just sprouted. Notice the half round leaves. 2) Pepper seedlings with their distinct pointy first leaves.
The 98 trays can be set in water holding trays, which can help keep the plants watered as they grow larger. However it is important to occasionally let the water tray dry out and water from the top as needed, this will allow the soil to dry out a bit so reduce fungus issues.
Transplanted 98 seedlings, go nicely into 2" or 3" pots, and will fill in and produce roots quickly.
Close up of Genovese Basil (on the left) and Tom Thumb Lettuce in the center. Single seeds grew quickly into big plants.
A nice mix of 98 cells on the right and larger 3" pots on the left. Looks like an instant garden. A bunch of the plants on the left are from cuttings.
Tomato transplants in 3 inch pots have quickly filled in and are almost to the point when they need to be transplanted again.
Here are some results of older seed trials this spring 2019.
Little Gem 2018: great germination.
Anuenue Lettuce 2015: poor germination, but some did sprout.
Argula Slo-Bolt 2017: great germination.
Green Deertongue lettuce 2016: good germination.
Cosmos 2017: good germination.
Pequin Peppers, collected seeds from 2018-2019 best germination of any peppers.