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Gardening Answers Knowledgebase

Plant Answer Line Question

Keywords: Antirrhinum, Capsicum, Seedlings, Tomatoes

I started some seedlings of tomato, pepper, snapdragon and lettuce in my sunroom under shop lights in peat pots. The temperature in the room is in the 60s at night and 70-80 in the day. I keep the soil evenly moist, but after 3 weeks, none of the seedlings that have germinated have true leaves. No secondary leaves of any kind. I cannot imagine why this would be under those conditions. Can you help me?


There are a number of variables that may be at work here. Are the seeds new? If not, were they stored properly? Also, seeds have varying lifespans. Some seeds require light to germinate and others do not. Some must be sown on or near the surface, and others must be sown more deeply. Seeds require varying degrees of heat. Oxygen is another requirement: is the seed-sowing mixture in your pots compacted? That might prevent germination. The steady moisture you are providing is good, and the temperature in the room is about right for most seeds.

University of New Hampshire Extension has useful general guidelines for starting seeds indoors.

The temperature of the water or the time of day in which the watering takes place may be influencing the growth of the plants. According to an Ed Hume's Garden Questions Archives article entitled, Starting Vegetable Seeds Indoors, seedlings should be watered with water that is just a little warmer than room temperature. If the water being used is too cold or if watering occurs in the evening as the temperature of the room drops, this could be slowing the plant growth.

I am wondering if the day time temperatures are too high. To quote from The Seed Starter's Handbook by Nancy Bubel (Rodale Press, 1988): "Plants grown indoors in warm rooms put on weak, spindly, sappy growth that is difficult to manage. Start seeds warm and grow seedlings cool."

Lastly, Starting from Seed by Karan Davis Cutler (Brooklyn Botanic Garden, 1998) says: "Since both heat and light fuel plant growth, the relationship between the two is critical. A common mistake among home gardeners is to keep plants at too high a temperature for the amount of light they receive. What often happens is that the gardener tries to compensate for slow growth with more fertilizer and higher temperatures. The result is limp, leggy seedlings that are hard put to cope with outdoor conditions. On cloudy days, the experienced gardener lowers the temperature to compensate for the lower light levels. While every plant has a temperature range it likes best, within that range, the cooler you keep the temperature, the better off the plant will be. Do not take things too far, though. A combination of low temperature, low light and overwatering is ideal for the development of damping-off fungus."

Date 2017-05-18
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Plant Answer Line Question

Keywords: Seedlings, Tree planting, Urban horticulture

We are planning to have a 'green' wedding, and thought about giving baby trees to our guests as favors, as a way of giving a gift that will leave an environmental legacy. Do you know of any sources?


I have had several questions like yours in the past, and I usually recommend substituting flower or vegetable seed packets, or perennials (including edible plants like herbs) for saplings. Many of the saplings available are conifers which mature into large trees--often too large for smaller home gardens, unless the residents intend to make them into bonsai specimens. Summer is probably the most labor-intensive time to plant a tree, because of the greater need for irrigation. That being said, there are numerous companies which market 'baby trees' (seedlings) as gifts. Here are just two examples:
Tree in a Box
Green World Project

If you want a green gift which is sustainable, I recommend giving low-maintenance perennial plants which have a high likelihood of survival even in a small home garden or apartment balcony. Another alternative is to donate an amount to an organization that reforests or restores natural areas, and then provide a certificate to each guest saying that a tree has been planted to mark the occasion of your wedding. See links to various organizations that take donations below:
American Forests
Arbor Day Foundation
The Heifer Project

Date 2017-05-26
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Plant Answer Line Question

Keywords: Plant identification, Seedlings

I have some seedlings coming up in my compost. They smell a bit like basil, but they could just as easily be weeds. I'd like to know if there are resources for identifying plants at this early stage of growth.


You could wait a week or two and allow the seedlings to develop, which might make identification a little easier. However, there are various resources online for identifying plants, especially weeds, at the cotyledon (seed leaf) stage.

There are also print resources which illustrate plants at the seedling stage:

  • Seeds of Woody Plants in North America by James A. and Cheryl G. Young (Dioscorides Press, 1992)
  • Woody Plant Seed Manual prepared by the Forest Service, USDA (1948), also available online
  • Seeds: The Ultimate Guide to Growing Vegetables, Herbs & Flowers by Sam Bittman (Bantam Books, 1989)
  • Park's Success with Seeds by Ann Reilly (Geo. W. Park Seed Co., 1978)
  • Park's Success with Herbs by Gertrude Foster and Rosemary Louden (Geo. W. Park Seed Co., 1980)
  • Weeds of the West edited by Tom Whitson (Western Society of Weed Science, 2000)
  • Weeds of California and Other Western States by Joseph DiTomaso and Evelyn Healy (University of California, 2007)

Date 2018-03-14
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Garden Tip

Keywords: Seedlings, Indoor gardening, Seeds

Seed racks are sprouting up at nurseries and grocery stores across the city - it's time to start seeds. One reason to start your own transplants is to save money. One packet of 50 marigold seeds typically costs the same as one 4" little start. The budget growing may extend into seed growing supplies by using recycled plastic pots from last season or even reusing individual yogurt containers or other comparable containers. "Growing chambers" can be made on the cheap from clear plastic bags and chop sticks to keep the moist plastic off emerging sprouts. The frugal gardener will be tempted to put those seedlings in a south facing window, but beware: Pacific Northwest windows are NOT bright enough to produce healthy, sturdy seedlings.

Invest in a 4 foot fluorescent shop light from the hardware store. It is worth the small amount of money. Buy one 40 watt cool tube and one warm tube, or if you're feeling extravagant buy the full spectrum grow lights, which will cost more. These lights should be replaced every year or at least every two years. Once your seedlings are up, the lights should be about 2 - 4 inches above the leaves. This can be tricky if you have plants growing at different rates. Try placing a platform under the short seedlings.
For a full explanation of fluorescent lights for seedlings go online to: http://www.garden.org/articles/articles.php?q=show&id=817

Date: 2007-04-03
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Garden Tip

Keywords: Seedlings, Lactuca, Brassica oleracea (Acephala group), Brassica oleracea (Capitata group), Reference books, Spinacia oleracea, Winter gardening, Vegetable gardening

While vegetable gardeners are inundated with zucchinis and other summer produce it can be hard to imagine the winter garden. But July is the time to plant seeds for fall and winter crops of cabbage, Asian greens, collard greens, spinach and lettuce. Transplants should go in the ground in mid August. Perennial and biennial flowers can also be started from seed right now. For an excellent list of what plants to sow throughout the year check out The Maritime Northwest Garden Guide produced by Seattle Tilth. It is available for $22.00, including tax and shipping. Call 633-0451 or order a copy online.

Date: 2007-03-05
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May 31 2018 13:14:08