Too busy to start seeds indoors? Don’t have a sunny south facing window or enough artificial lighting to properly grow seedlings inside? Or maybe it’s already too late…Don’t give up on sowing your own seeds just yet.
Plant Seeds Directly Outside EARLY
Plant directly outside under a homemade mini greenhouse and create your own ecosystem that keeps the seed moist and protected despite unpredictable temperatures.
It’s easy to miss the window for starting seeds inside. Gardeners have great hopes as the weather warms but find themselves behind schedule when it comes to producing viable transplants. Starting seeds inside requires some planning. Identify your last frost date in the spring, and count back a certain number of weeks to find the “best” time to plant inside.
COMMON INDOOR SEED STARTING PROBLEMS – As seedlings get larger inside they need more nutrients, space and light. Both inexperienced and experienced gardeners make the mistake of not providing enough light to young seedlings causing them to desperately stretch toward the light source. They become weak and leggy.
For tomatoes you would need to start seeds 6-8 weeks before your last frost date in the spring. Generally, the timetables below would apply.
- Zones 1-4: Start seeds indoors in mid to late March
- Zone 5: Start seeds indoors in early March
- Zone 6: Start seeds indoors in late February
- Zone 7: Start seeds indoors in mid February
- Zone 8: Start seeds indoors in early February
- Zones 9 & 10: Start seeds indoors in early to mid January
Don’t know your zone? No worries! You can look it up at the bottom of this page without leaving this site.
Most folks transplant seedlings outside two weeks after their last frost date. We all know that the last frost date cannot be predicted with perfect accuracy. Therefore, you are estimating when it is safe to transplant and hoping for the best – unless you wait until the risk returns to 0%.
Why Is Planting Directly Outside Beneficial?
Many of us miss the golden opportunity to start tomato and other warm weather vegetables inside. That’s not a setback. In many cases, you can plant seed outside before you would set transplants out!
Another potential advantage is improved robustness and less chance of a pest infestation. Plants grown from seed outside from the beginning may harbor less pests and grow stronger because they develop from start to finish in their permanent home in their native soil. Nursery seedlings have been fertilized and nurtured under controlled commercial greenhouse conditions. Often times, the store bought seedling suffers a bit when transplanted. It’s stressed in its new environment where it doesn’t get the same attention, chemicals and treatments it got by the growers. There also may be pests stowed away on purchased seedlings.
To learn more about toxic-free pest control check out our latest eBook. For all eBooks and electronic downloads, take a look at our Digital Library. We currently have a FREE download in the bookstore.
How Do I Make a Mini Greenhouse?
You can buy expensive “cloches” that look fancy and have built-in vents. Or you can save your money for other fun stuff and instead make your own cloches out of large water or milk jugs.
Simply cut water or milk jugs in half. You’ll get two mini greenhouses out of one bottle. If there is a handle, cut the bottle so that one half has the handle intact. Poke a hole in the other half of the bottle and use wire or stakes to secure the bottles to the ground.
How Early Can I Plant Directly Outside?
When to plant directly outside under protection depends on your current temperatures and threat of frost. Are you experiencing warm days, above 65F (18C)? Are nights cool but stay above the mid 40’s F (7 C)? If the answer to both questions is “yes” and the first day of spring has passed, you can start your seeds early outside with some success. You may even have 100% success. If you follow the tips below, especially the tip entitled “LET THERE BE HEIGHT AND HEAT”, your chances of success skyrocket!
Bottle Greenhouse Planting Guide
Use this handy guide to decide when to plant seed directly outside under bottle greenhouses (look up your zone if needed at the bottom of this article):
- Zones 1-4: Start warm season vegetable/fruit seeds directly outside under bottles starting in May.
- Zone 5-7: Start warm season vegetable/fruit seeds directly outside under bottles starting in mid April.
- Zone 8: Start warm season vegetable/fruit seeds directly outside under bottles starting in mid January.
- Zones 9 & 10: Start warm season vegetable/fruit seeds directly outside anytime unless you experience a wet season and your planting area is not raised and gets flooded!
The zones listed are generalized. Always consider your specific climate when deciding when to plant outside under bottle greenhouses. For example, if you live in Zone 5 but high in the mountains or in a micro-climate where nights get much colder than surrounding areas, you may need to start seeds outside a bit later, or grow the plants to maturity inside a crude greenhouse. Other factors: Are you planting in a location that does not get sufficient light or that seems to be an anchor point for frost?
In Cooler Climates, Choose Plant Varieties Meant For Short Growing Seasons
Even northern gardeners should be able to find tomato varieties that grow to maturity in two months!
Too Hot to Handle
If you live where temperatures go over 100 F frequently, use shade cloth to shelter the plant and wait until temperatures drop for pollination to occur. We do this and harvest tomatoes until New Year’s Day – IN ZONE 7!
What Kind of Soil Works Best Under a Bottle?
There are several tricks of the trade for successfully starting seed outside before temperatures thoroughly warm up. If you just stick seeds in the ground without paying attention to the soil you will probably get less than favorable results.
Prepare a fine-textured seed starting mix that will retain moisture and allow the seeds to sprout in a friendly environment. Your chances of germination may be so much greater if you sow the seed in a medium that stays moist and allows an open path to break ground. You can purchase seed starting mix or make your own – our preferred method!
Simply screen compost through a strainer or old window screen to acquire a soft material, free of rocks and chunks of bark or tree trimmings. Then mix the same amount of vermiculite into the compost. Vermiculite is a MUST. This important substance is a mineral that resembles mica in appearance. It holds moisture and will allow the seed bed to stay moist in between waterings. Combined with the screened compost, you will have a very good seed starting medium for the mini greenhouse. Vermiculite can usually be found at garden centers and large home stores.
NOTE: Most seeds do not need nutrients to sprout. Some seeds, like tomatoes do not even need light to sprout. Once they’re up and stretching toward the sun, they do need nutrients and light. Therefore, feel free to add worm castings and kelp granules to your batch of seed starting mix. A cup of worm castings and a tablespoon of powdered kelp would work well for every gallon of seed starting medium. Estimate the best you can. Perfect ratios are not necessary. We do not recommend synthetic fertilizers – EVER! Learn why in our popular eBook “50 Homemade Fertilizers and Soil Amendments”.
Keep It Moist
You can’t plant and “forgetaboutit”. You’ve got to check on the area periodically. Don’t let the soil dry out. If you plant in raised mounds, the seed should never be flooded or rotting. The beauty of using clear jugs is that you don’t need to lift them up to see how the seeds are coming along. For frosted bottles, keep the cap on and remove to peek inside. Then replace. Water your seed starting medium with a mist to avoid disturbing the developing seed with a forceful jet.
Let There Be Height AND HEAT
Raised beds generally warm up 2-3 weeks earlier than ground plots. Start your seeds in raised beds to take advantage of warmer conditions. Also consider layering mounds of native soil, compost and tree trimmings to create active compost heaps below the seed. The heat from the composting process below will keep developing seeds cozy longer.
Good luck with your outdoor seed starting!
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