Hi mtgs,
farms I have worked on have all had their own ways with salad mixes. (I assume that's what you mean and not those micromicro greens that are basically sprouts?) Here are some:

* make a mix before sowing - use the seed catalogues or another reference guide to check how long until they will be ready for havest (days to maturity). You might need two mixes - one for fast and one for slow producing greens.
* cut leaves and mix after sowing - pretty straightforward and allows you to balance your mix as you pick depending on what is doing well
* cut whole lettuces (at close to full size) and break them up for mixes. This method suprised me but worked pretty well at one farm where bagged salad mixes were a large part of the crop. (up to 20kg a week). We used transplants and I guess this just meant that we got more bulk out of each planting.

Personally I have come to hate salad mix - the labour in picking and washing and packing never ends! But it is an important part of most small market gardens, I guess because the yield for a small space is so good and the season is so long.

I have been looking into micro greens, most the info I have gathered suggests you grow in mats of product that goes to goes together. Ie. salad greens like chard and arugula then mats with herbs. I don't know much about it, still learning.

I mix after harvest. This is to eliminate working with different germination rates and to simplify my harvest. I sell some (really a very few) growing in trays and customers have asked for mixes in them. So I may try it, but my real purpose of the micros in trays is to make my display look nice as trays are not so easy to transport.
I was thinking of growing some purple and green radish in trays in bands to look cute in the display, but really don't want to bother mixing different things in trays and deal with different germination times.

We have been growing and selling micro greens for about 6 years at market. This is how we do it. We use what we call a saucer, it is about 14 inches in diameter and about 2 inches deep. We grow hydroponically so we use coir as our growing medium but I would think, any good potting soil mix would work. We buy pre mix micro green seed fom who ever has the best price.and mix it all togather. We dampen the coir. Then we have an over size pepper shaker and sprinkle the seeds on the coir.. We use a heavy amount of seed because you want a thick layer of sprouts when it starts to grow. When the sprouts are about 2 inches high, we take the sauscers to market and sell them for $15.00 each. We list all the different seeds we have used on a 8 X 11 sheet and tell the customer, they may get any and/ or all of the different seeds. We tell them when the sprouts are about 3-4 inches tall, to cut as much as they want to mix into there salad. When they cut the greens, be sure and leave a few leaves so it will continue to grow back. NEVER pull the roots out.The micro greens are an adjunt to the base salad. We tell them if they feed and water it, and keep out of the hot sun, they will be able to get 3-4 cuttings out of a saucer. We suggest 2 tablespoons of miricle grow to a gallon of water, water around the edge, keep it moist, not wet. That is how we do it, and we usually quit selling them at the end of June. Hope this helps

What do you plant in the coir? We want to try this

Oh and where do you recomend buying the seeds. Some places are much pricier than others?

Hi rio grande. Coir is ground up coconut. I have no idea where they came up with the name. I buy it by the 2 cu ft. bag and in WA it costs me around $10.00. You can fill a lot of saucers with a bag. I buy the seeds from whomever has a good price. It might be Johnny's, Territorial, Guerney . Just go through all your seed catalogs and look for micro green seed mix. Hope this helps and good luck.

Thanks just got my choir and plates, Johnny's seed package arrived today so you can guess what I am gonna try tomorrow!