{"id":20032,"date":"2024-03-09T12:33:54","date_gmt":"2024-03-09T20:33:54","guid":{"rendered":"https:\/\/extension.wsu.edu\/yakima\/?p=20032"},"modified":"2024-09-03T13:02:04","modified_gmt":"2024-09-03T20:02:04","slug":"germinating-seeds-indoors","status":"publish","type":"post","link":"https:\/\/extension.wsu.edu\/yakima\/2024\/03\/09\/germinating-seeds-indoors\/","title":{"rendered":"Germinating Seeds Indoors"},"content":{"rendered":"\n

Originally published March 9, 2024 in the Yakima Herald-Republic<\/em><\/p>\n\n\n\n

by Carol Barany<\/p>\n\n\n\n

Joe Gabriel is the best vegetable gardener I know. Maybe it\u2019s his homegrown seedlings. For 50 years, he\u2019s started thousands of seeds with spectacular results, and a few spectacular failures. An area 2\u2019 x 4\u2019 on a basement workbench is all the space he has to start hundreds of seeds each year.<\/p>\n\n\n\n

Many of us are itching to start some seeds. With Joe\u2019s range of experience, there was no one better to ask for some wise advice to get us started.<\/p>\n\n\n\n

Light<\/h2>\n\n\n\n

Seeds need 16 hours of light each day, and the sun\u2019s winter arc won\u2019t provide enough. Seeds may germinate on your window sill, but will grow weak and leggy, even if you turn the plants daily. Many gardeners supply supplementary light with ordinary LED or fluorescent shop light tubes. Joe feels that the \u2018grow light\u2019 tubes he prefers are worth the extra cost because they offer full-spectrum light. Hang the lights you choose 2\u201d- 3\u201d above
the soil surface and raise them as the plants grow.<\/p>\n\n\n\n

Most seeds benefit from bottom heat for germination, and Joe starts his on heat mats. He doesn\u2019t use domes, the transparent covers placed over seed beds to increase humidity. they\u2019re included in standard seed-starting kits and many find them helpful. Be sure to remove the domes after the seeds sprout. New plants require better air circulation.<\/p>\n\n\n\n

Seed Sowing<\/h2>\n\n\n\n

In a 4\u201d pot, Joe plants 3 rows of seeds. For example, a row might be a single variety of tomato, pepper, or eggplant. He\u2019ll plant 3-4 seeds\/row for a total of 9-12 seeds\/ pot. Each row is carefully labeled with the variety name. <\/p>\n\n\n\n

Timing<\/h2>\n\n\n\n

Joe starts seeds for frost tolerant crops like cabbage, broccoli, cauliflower, lettuce, spinach, and cilantro on February 15. He may seed these again in late June for fall harvest. Tomatoes, eggplants, and peppers are started the first week of March, followed by tomatoes March 15.<\/p>\n\n\n\n

When seedlings develop two sets of true leaves, they\u2019re \u2018bumped up\u2019 into individual 3\u201d- 4\u201d square pots.<\/p>\n\n\n\n

His frost tolerant seedlings are planted outside on March 1 under his homemade cloche\/row cover. If you don\u2019t have frost protection, he advises backing up sowing and transplanting dates for cold crops about 3 weeks.<\/p>\n\n\n\n

Warm season varieties grow on in his small unheated greenhouse until May 12, the ‘Average Last Frost Date\u2019 for his 98902 growing area. Started too early, seedlings can become overgrown before it\u2019s time to transplant them outdoors. Started too late, they won\u2019t have enough time to produce a crop. Unless you have row covers, a cold frame, or greenhouse; continue growing your seedlings under artificial light until it\u2019s safe to plant
them outside.<\/p>\n\n\n\n

Not all plants are cut out for transplanting. For example, radishes, carrots, and beets grow best seeded directly into garden soil.<\/p>\n\n\n\n

I\u2019ve learned the hard way that I don\u2019t need a whole seed packet worth of zucchini plants. Joe plants only what he needs, plus a few more seeds for insurance. He also succession seeds some crops, like salad greens, at 7-21 day intervals to maintain a steady supply. Extra seeds are stored in a zip-lock bag in the freezer.<\/p>\n\n\n\n

Soil<\/h2>\n\n\n\n

Seeds need a lightweight, nutrient-filled planting mix that drains well and allows roots to expand quickly. Called \u2018potting soil\u2019 they are usually soil-less mixes containing a combination of peat, perlite, vermiculite, coir, and compost. Some seeds, especially those that are small, may do better in an especially porous and fine-grained \u2018seed-starting mix\u2019. Never use topsoil or garden soil. <\/p>\n\n\n\n

Water<\/h2>\n\n\n\n

As soon as a seed is planted and begins absorbing water, the soil should never dry out or become saturated. Seed starting for Joe is not a \u201cset it and forget it\u201d endeavor. He consistently monitors the needs of his growing seeds. If he\u2019s leaving town, even for a few days, he finds a seedling babysitter.<\/p>\n\n\n\n

\u2018Bottom watering\u2019 is preferred. Joe\u2019s seedling pots sit in Dollar Tree aluminum pans. Adding water to the pans allows the seedlings to wick up water through the drainage holes in their pots. Standard seed starting kits contain a tray that serves as a liner for bottom watering.<\/p>\n\n\n\n

Fertilizer<\/h2>\n\n\n\n

Since seedlings are growing in a soilless mix that may not contain fertilizer, they\u2019ll
need supplemental feeding when their true leaves develop. Use a half-strength water-soluble fertilizer every two weeks, or add a slow-release granular fertilizer at the time you transplant into individual pots.<\/p>\n\n\n\n

Hardening Off<\/h2>\n\n\n\n

Planted directly into the soil without ever being outdoors before, most seedlings won\u2019t survive. Two weeks before planting day, begin setting them out for a few hours daily so they can adjust to fluctuating temperatures, light intensity, and winds. If you can, plant them into the garden on a cool and cloudy day to minimize \u2018transplant shock.\u2019 Keep them well watered for the next 2 weeks while they establish a strong root system. The internet offers hundreds of hours of \u2018How to Start Seeds Indoors\u2019 tutorials. I think I read or watched them all before I talked to Joe. These two are among the best: <\/p>\n\n\n\n