Germination trials or an overview of Experiment Number One

The first thing we are going to be looking at are seed germination rates in different low tunnel treatments within the greenhouse.  The goal is to create a low tunnel that will significantly decrease the time it takes for seeds to germinate.  In cold weather seed germination can sometimes be a limiting factor in plant growth.  For example, lettuce will germinate best around 68 degrees Fahrenheit, but will happily grow at much lower temperatures.

Here's an overview of what is going to happen:

The six low tunnel treatments

1. Clear plastic - the thick stuff used to cover greenhouses
2. White plastic 
3. Clear plastic with holes - a light weight plastic with holes that allow for ventilation
4. Floating row cover - often called 'remay' on farms
5. Heat mats - to provide bottom soil heat
6. Control - just plants in the greenhouse

The three varieties of greens

• Spinach - the slow germinator
• Lettuce - the mid-rate germinator
• Mizuna - the fast germinator

Why only these three greens?  To properly conduct a Scientific Experiment there have to be lots of replications.  For instance, if we do six replications of 24 plants per treatment that ends up being almost 2000 seedlings to plant and count for each species of green.  To keep the counting low-ish we picked three greens that represent a range of germination from fast to slow.

An abridged protocol

1. Finish building the low tunnels.  This involves drilling into metal using tech screws.  I am not good at this and have been putting it off.
2. Plant a lot of seeds.  They haven't arrived yet which is why I can put off the drilling.
3. Count the number of seeds that have germinated every day for ten days.  

That's it!  I'll be writing about the process and results as they unfold with plenty of pictures.

Greenhouse or tunnel?

High tunnel

looks like a typical greenhouse but is not heated.

Greenhouse

has a source of heat like propane.

Low tunnels

temporary structures that look like mini-greenhouses.  

Sides are held down with sand bags or dirt and have to be uncovered for harvesting.

plant profile: Mizuna

Brassica rapa juncea

(kyona, shui cai)

Appearance - Mizuna is an upright green with deeply cut serrated leaves on thin white stalks.  It is part of the hot and spicy group of mustards in the Brassica rapa family but has a mild flavor.  It can tolerate both heat, humidity and cold weather making it a good year round crop.  

Uses - Originally, mizuna is from China but is thought of as a Japanese green that is primarily used for cooking.  Here in the west is mainly used as a salad green but as it becomes more well known its uses are growing to include stir fries and stuffing for raviolis.

Varieties

Culture - Mizuna is easy to grow and should be treated like other Brassicas.  Sow seeds 1/4 inch deep in moderate temperatures between 60-85.  Once the seeds have sprouted temperatures a bit lower, between 55-75 degrees, is sufficient for growth.  

For baby greens seeds should be sown in 2-4 inch bands with 60 seeds per foot.  For larger leaves sow only 15 seeds per foot in 2 inch wide bands in rows 18 inches apart.

Harvest - Baby greens should be ready for harvest in about 21 days, depending on temperature and light levels.  Full sized leaves should be harvestable in 40 days.  Mizuna is a cut-and-come-again crop and will produce multiple harvests.

Pests - Like all Brassicas flee beetles are the major pest of mizuna.  Using floating row covers is an easy method of controlling these pests.  For more information check out the UNH Cooperative extension's page on flee beetles.

Wednesday quiz: how do you like your lettuce?