📌 Quick Summary (TL;DR): Mid-April Greenhouse Planting Risks & Rewards
- 🍅 Early Tomatoes: Planting tomatoes directly into the cold greenhouse dirt in mid-April (Zone 4) is risky. Growers use heavy frost blankets, plastic film, and 1.3-gallon (5L) jugs of hot water placed near the plants at night as thermal mass to keep them alive.
- 🦆 Greenhouse Pests: Watch out for sneaky livestock! Free-ranging ducks love to sneak into open greenhouses to devour early spring lettuce greens.
- 🥒 The “Hot Bag” Zucchini Hack: You can grow early heat-loving crops like zucchini in a freezing greenhouse by making a mini-hotbed in a feed sack. Fill the bottom with chicken manure, activate it with boiling water, add soil, and plant! The composting manure keeps the roots toasty warm.
Photo author: EMILIA
Nessie wrote (Apr 14, 2021):
I am feeling like a superhero today. I planted my seedlings out into the big tomato greenhouse!
I just planted half of my greenhouse with tomatoes too! The other half is filled with my tissue-culture (in-vitro) seedlings, and later I’ll grow watermelons and cantaloupes on that side. My husband and I also put together a small bed for our ‘Kupchikha’ and ‘Toscana’ strawberries.
Also, it turns out a sneaky Muscovy duck got into the habit of raiding the greenhouse to nibble on my lettuce. I caught her red-handed today! The funniest part is that the drake was literally standing guard at the door while she quietly slipped in. She started squeaking indignantly when I chased her out. And here I was wondering why my lettuce was going bald! 😂
Oh, and I also planted a ‘Cavili‘ zucchini into a sack today, it already has two true leaves!
Maria Suvorova wrote:
I just planted half of my greenhouse with tomatoes too!
😲 Wait, directly into the ground beds? Or in bags? Do you have a space heater in there? How are you warming up the soil?! Either way, that’s awesome.
Tatunya (Tanya) wrote:
How are you warming up the soil?!
I’m not heating it at all! Let them live like that. I’ll cover them with frost blankets and plastic film if a cold snap hits. Plus, I put out 1.3-gallon (5-liter) jugs filled with hot water at night. If it gets dangerously cold, I might just have to go sleep out there in the greenhouse with them to keep them warm! 😂
Maria Suvorova wrote:
I just planted half of my greenhouse with tomatoes too!
Well, peer pressure is contagious, I think I’ll go pop mine in the ground too! My seedlings are already big and sturdy, I can plant them normally without trenching them deep. As for the cold… if they want to live, they’ll survive! 😅😁
brilliant (Galina) wrote:
Well, peer pressure is contagious, I think I’ll go pop mine in the ground too!
I just went and checked my seedlings that I brought out to the greenhouse a few days ago. They got so strong and stocky, they’re even pushing out flower buds. They are absolutely begging to be planted. The ground actually feels warm. I don’t know the exact temperature, but it feels no colder than it did in early May last year.
Maria Suvorova wrote:
Oh, and I also planted a ‘Cavili’ zucchini into a sack today…
Good afternoon everyone. Maria, what exactly did you fill that sack with, and where did you put it? Inside the greenhouse? I really want to try this. I assume this is purely to get a super early harvest, right?
Clever (Irina) wrote:
Maria, what exactly did you fill that sack with…
Irina, I take a woven poly sugar sack (like a heavy feed sack) and stuff the bottom with soiled bedding straight from my chicken coop. Then I pour about 2.6 gallons (10 liters) of boiling hot water* right over the manure.
After that, I throw about 4 inches (10 cm) of regular potting dirt on top and plant the zucchini seedling in it. I leave the edges of the bag rolled up so it forms a little protective “house” around the plant. You can also throw a piece of frost blanket over the top. I keep the whole setup sitting in the corner of the greenhouse. Boom, early zucchini!
There is some serious old-school homesteading magic happening in this thread! Let’s break it down:First, Maria’s “Hot Bag” technique relies on the scientific principles of hot composting. By packing a bag with raw, nitrogen-rich chicken manure/bedding and soaking it with boiling water*, she jumpstarts an intense bacterial breakdown. The manure acts like a biological space heater, warming the soil above it so the heat-loving zucchini roots stay toasty, even if the greenhouse air drops near freezing in April!Second, she specifically chose the variety ‘Cavili’ (Cavili F1). This is a highly popular Dutch commercial variety that is parthenocarpic, meaning it sets fruit without needing to be pollinated by bees. This is a crucial detail! If you try this early spring greenhouse trick with a standard zucchini variety (like Black Beauty), the flowers will just fall off because there are no bees flying inside a closed greenhouse in April. (US growers: ‘Partenon’ or ‘Sure Thing’ are excellent parthenocarpic alternatives to ‘Cavili’).

