Drip system is complete!

I spent a sunny Tuesday installing the mister/foggers (one per flat) and a drizzly Saturday making the rest of the connections for the hanging baskets in the greenhouse and the flats on the second shelf below. I learned a couple of tricks along the way.

I attached the 1/2-inch mainline to the metal supports on the side of the greenhouse and used a plant hanger to arch it up over the tomatoes (toward the back).

Inserting the connector into the 1/4-inch tubing is a bit of a challenge. I learned to stick one end into a knot and then push with both hands to get the tubing over the connector. The knot held the tubing in place, freeing up my other hand. I got them all on, all the way. I also had a tough time getting the tubing going to the flats on the second shelf to bend the way I wanted them to, so I wrapped them in wire and then bent them into position. It worked moderately well.

For the hanging baskets, I ran 1/4-inch tubing from the mainline over to the baskets and used fogger/misters attached to a stake on each except the one above the fan. I don't want to spray the fan, so I used a dripper there. I haven't tested it yet since nothing needs water and it has been raining all weekend. In fact, I noticed that the self-operating vent does not quite close right now, so water drips in when it's raining and drowns one of my baskets. I slid the basket attachment up the ceiling so that the drips would miss it. The mister/fogger on the stake is angling upward now; I am hoping it will still do the job and not miss the basket entirely.

Today, I dug out a chicken light fixture to put my special grow light for the tomatoes in and hung it up. I not only have a cherry tomato up, but also a yellow tomato. There are also three others coming up in other places. I think they are in flats that had dirt in them last summer, so the tomatoes I had in the greenhouse all summer and fall must have dropped a few seeds here and there. Excellent!

My 24 tomato plants to be are bathed in the purple glow light. At 12 watts, it doesn't seem to be heating up.

Right behind and to the left of the Black Plum tag is the cherry tomato, and the golden tomato is to the left of the Ancho tag.

I put the light on a timer. It comes on at 2:30pm and goes off at 10:00 am. That way, it won't be on longer than 18 hours (recommended for the light), and the time that it is off is the brightest time in the sunroom and also when I will be watering. The timer I bought will do 20 on and off cycles. It would be a good one for the fan.I may switch it out with the one in the chicken barn because it apparently has two plugs I can program separately (i.e. one for the fan and one for the grow light).

The light has red and blue lights, so looking out at the greenhouse, it looks purple. Kind of pretty!

Besides the golden tomato being up, I have a teeny tiny impatiens up.

I don't even think you can see the little green seedling (the impatiens, it's to the right of the stake), but you can see the mister/fogger on a stake.

I noticed some slug damage on these little broccoli seedlings, so I put some organic bait out. I finally found the culprit, too. I think I see evidence of slug damage on the other side, too, so I'll have to put some over there, too.

For those of you unfamiliar with slug damage, the seedlings on the left should have leaves. Even the leaves of the one in front have bites taken out of them.

The daffodils we planted on a cold, rainy day in November burst open this week.

Wouldn't you know it? As soon as the daffodils start to bloom, the rain comes and weighs them down. I snapped this photo before the rain set in.

Humidity and the greenhouse: a tale of two variables

Moisture and temperature. That's what I somehow have to balance in my greenhouse.

I found out first-hand last year that humidity is important to control in the greenhouse. I am growing vegetables and flowers to transplant into the garden later this spring, so I need to find out what conditions are best for these plants.

Too much humidity

While there is no ideal humidity, you don’t want your plants to be too wet. Wet leaves can lead to fungi, such as Botrytis, or powdery mildew. When moisture builds up in the greenhouse, droplets form on the ceiling and drip down onto the leaves of plants. The splash can cause the fungus to spread to other plants, or it can hit the soil and splash up onto plants.

Botrytis blight on a peony leaf (http://www.missouribotanicalgarden.org/gardens-gardening/your-garden/help-for-the-home-gardener/advice-tips-resources/pests-and-problems/diseases/fungal-spots/botrytis-blight-of-peony.aspx)

Powdery mildew on a squash leaf (http://www.missouribotanicalgarden.org/gardens-gardening/your-garden/help-for-the-home-gardener/advice-tips-resources/pests-and-problems/diseases/fungal-spots/botrytis-blight-of-peony.aspx)

When the greenhouse heats up during a sunny early spring day, moisture evaporates and the warm air holds it. When the temperature falls at night, the air cools and the moisture condenses—back onto the leaves, soil, and greenhouse surfaces, causing drips from the ceiling. It is crucial to keep the plants dry from dusk to dawn.

Controlling humidity

Keeping the air moving during the day by way of vents and doors helps the suspended moisture leave the greenhouse. My greenhouse has one self-ventilating window in the ceiling, but one open window is not enough. You need to have moving air, so opening a door to create a cross breeze will help the moisture escape. However, if you want to keep the temperature up in your greenhouse (because inside it’s 80 degrees but outside it’s 45 degrees), opening the door is not a good option. That’s where a fan comes in. It will help move the air, especially if you point the fan toward the open vent from across the greenhouse. The other option is to keep your greenhouse warmer at night so that the temperature does not drop too much. This can get a bit expensive though.

My wall-mount oscillating fan

The self-opening vent in my greenhouse

Complicating matters is relative humidity, which differs depending on air temperature. The warmer the air, the more moisture it can hold. The higher the relative humidity, the higher the temperature at which condensation will occur.

Avoiding excess water

It is important that water does not puddle in the greenhouse during the day, which would then evaporate and cause unnecessary additional moisture. The amount of water plants get during the day needs to be just right and will depend on how hot it gets inside your greenhouse. You don’t want the top of the soil to dry out, for example, if you have just planted seeds. Also, it is better to water early in the day to allow plants to dry before evening.

Heat

Apparently it is best to alternate between venting and heating your greenhouse at least two to three times per hour in the morning and evening hours. For me, I have decided to only use the heater to prevent freezing temperatures, so I will likely see what kind of relative humidity drop I can achieve without dropping the overall temperature too much. In other words, I won’t be cranking the heater up just after using the fan. I will have the fan on a timer, turning it on low (the leaves should move slightly) and then off, on and then off, several times in the morning and the evening. I am thinking that I will only need to have the fan on for two or three minutes at a time to start, and then adjust as the weather varies.

The chart below indicates the temperature and relative humidity that is adequate to prevent fungal growth and/or disease:

50°	83%
61°	89%
68°	91%
86°	95%

A few questions remain:

• My humidity gauge only gives me humidity and temperature, not relative humidity. How do I figure out the relative humidity?
• If my temperature is 86 degrees and my relative humidity is 90%, is that good?

(Sources: https://extension.umass.edu/floriculture/fact-sheets/reducing-humidity-greenhouse; http://homeguides.sfgate.com/ideal-humidity-level-greenhouse-77050.html)

Today, I installed the foggers and misters in my greenhouse, as well as my fan. I preferred the foggers but used two misters and three foggers on each side. I tested their reach out today and ended up with way too much humidity in the greenhouse. I still have some finessing to do, but I am pleased with the layout. Details of the foggers/misters' spray radia, as well as pictures, will follow soon.

Seedling update: lots of basil up now! And one lonely cherry tomato. I have them in the highest, warmest spot in the greenhouse.

The basil is tiny but doing well.

One little tomato planted finally popped up (in back).