This Guide is intended as a general introduction to planting and raising seeds. While we have endeavored to answer as many questions as possible, no document of this size can hope to be all encompassing. We therefore encourage you to seek additional locally-specific information from your agricultural or university extension office.
Begin at the beginning
As early as possible in the year, prepare a list of the vegetables, flowers, and herbs you want to grow. Obtain the seed for them or, if too late to start your own plants this year, opt for locally-purchased plants and plan to be earlier next year. Plants which mature quickly such as beans, leaf lettuce, radishes, etc. can be planted even if you purchase your seed well past the last frost date in your area. It is also possible to grow a second crop or Fall Garden by starting many seedlings in late June and July for planting and harvesting up to the First Fall Frost. Plan out on paper where in the garden you will put your plants, taking advantage of windbreaks, shade, and sunlight hours. Save the paper and add notes as your garden progresses. A full and accurate garden record is as essential a tool as a spade or trowel.
The importance of the Last Frost Date in Spring
There are two categories of plants in the garden:
Frost tender plants which will be killed by temperatures of 32 degrees or less. This group is further divided into those which must be started indoors so that they have grown into small plants before planting after the last Spring frost and those which will simply be direct seeded into the garden soil after the frost date.
Hardy plants will not be killed if your early Spring temperatures drop into the lower 30’s. These can be planted directly in cool soils without pre-starting in the house.
Find out your Last Frost Date
You can ask gardening neighbors, call any local agricultural or university extension offices, ask at a garden supply or nursery or at the feed store, or consult a map through several on-line sources. With this date you can now work backwards through the early Spring months and work out what needs to be started and when.
When (and Where) to start your seeds
|Vegetable||Weeks Before Last Frost Date|
|Start indoors and transfer outdoors after last frost (These plants are tender)|
|Chives; Globe Artichoke; Leeks; Onions;||12|
|Eggplant; Peppers; Tomatillo; Tomatoes;||8|
|Broccoli; Cabbage; Cauliflower;||6|
|Cucmbers; Melons; Okra; Pumpkins; Squash;||3|
|Direct Seed in garden before last frost (These plants are hardy)||Weeks before last frost date|
|Onion Sets; Seed Potatoes;||6|
|Kale; Kohlrabi; Spinach; Turnips; Mustard;||5|
|Beets; Carrots; Chinese Cabbage; Endive; Peas (English); Radish;||4|
|Lettuce (all types); Swiss Chard;||2|
|Direct seed in garden after last frost (Tender)||Weeks after last frost date|
|Beans; Celeriac; Cowpeas;||1-2|
|Corn; Muskmelon; Watermelon; Okra;||2|
|Cucumbers; Peanuts; Amaranth;||2|
Starting Seeds Indoors
Collect the necessary materials for starting seeds. You will need pots or other containers, soil medium, and plastic bags or wrap. Containers can be anything from yogurt cups to purchased flowerpots, but all should have drainage holes in the bottom so there is adequate drainage for your seedlings. Egg cartons are too shallow; there should be about 3” of soil medium in the container to encourage proper growth of the young roots. For “soil” buy bags of seed starting mixture (note to Organic Growers – may contain chemical fertilizers; read the bag carefully) or make your own. Good soil-less mixes can be made from 50% peat moss with 50% vermiculite, or buy bags of potting soil and add 50% peat moss: that is 1 quart peat moss to 2 quarts potting soil. Potting soil used by itself is too heavy and packs down easily. Garden soil (dirt), in addition to being too heavy, contains many microbes, including some disease bacteria which may attack your young plants, causing early death.
Moisten all mixes before planting the seeds. Plastic bags or wrap will keep the moisture in your seed trays and aid in faster germination. Fill your containers with the moistened mix and press it down into the container so that you have a firm bed for the seeds. You don’t want them to fall down to the bottom of the container and not germinate! With a stick or pencil, create a little trench in the soil or punch a small row of shallow holes. Very important note: most seeds should be buried to a depth of one or two times the diameter of the seed. For instance, this means that small seeds like tomatoes should barely be a quarter of an inch below the surface of the soil. Remember that in nature most seeds just lie on the surface of the ground before germinating. Having planted your seeds, take care not to overcrowd them; very lightly press a little more soil mixture on top and lightly mist with water. Place the whole container in a clear plastic bag or under a sheet of plastic wrap. Remove it immediately after the first seed germinates.
In addition to requiring a soil medium and water to grow, seeds also require warmth and light. A warm spot in the house, such as on top of the refrigerator, will provide the heat. Seedling heating mats with thermostatic controls may be purchased. Once the seedlings have emerged, light becomes extremely important. A sunny windowsill may have to suffice, (remember to turn the seed trays every other day), but ideally a pair of low-cost fluorescent shop lights should be suspended on chains about 2 to 4 inches above the growing tops of the seedlings. Turn the light on for up to 16 hours per day and then let the plants rest during 8 hours of darkness. Keep the seedlings warm during the day hours (70º) and reduce the temperature to 60º at night. Lightly water when the soil feels dry to the touch using water at room temperature. Check often as soil mix dries out quickly in heated indoor conditions.
When the seedlings have grown their first set of true leaves (which are the 3rd and 4th to emerge), they should be fed with a diluted liquid feed. This can be a commercial houseplant food diluted to 50% weakness with extra water, or a fish and kelp emulsion organic food (note: this will smell “fishy” for some hours after use). At this time also, seedlings can be moved up into larger containers if needed. When transplanting seedlings into larger containers, hold the young plant by the leaves and not by the stem. The leaves, if damaged, can be replaced as the plant grows taller, but if the stem is damaged by rough handling the plant will likely die.
What went wrong with my seedlings?
Didn’t germinate at all or very few germinated–There are a few possible causes to this problem. The first may be old seed and/or kept in poor storage conditions. Seed sold commercially is sold for use in that season and has been tested and shown to have a germination rate of at least 80%. Seed that has been kept for more than a year in less than ideal conditions (for instance in a warm or moist place) may then not germinate up to the known percentage. Some seeds take a very long time to germinate, and perhaps you have simply not waited long enough—celery and parsley seed, for instance, can take at least 21 days to germinate. If your soil temperature is too cool, seeds will take a long time to break their dormancy. Eggplants and peppers like temperatures around 75º to 80º and slow considerably when started in cooler conditions. Excessive watering may have rotted the seed in the soil mix before it even had a chance to sprout. The soil mix should be damp but not dripping.
Seedlings that grow normally and then drop over or that show signs of fungus or mold are likely victims of dampening off, a bacteria-borne disease. To avoid this condition, always use a soil-less mix which is sterile and rinse thoroughly all containers with a bleach and water solution (1 part bleach to 10 parts water) before use. Dip your tools in this same solution and ensure that your hands are always clean when handling seedlings, especially if coming in from outside gardening chores. A chemical solution of Benomyl fungicide can be used in greenhouse environments to control these diseases. Water from the bottom whenever possible. This means standing the pots in a shallow pan of water and letting them soak up the liquid rather than using a watering can.
Pot-bound seedlings have been growing too long in a container which is too small. Likely all nutrients in the soil have been exhausted and the plant needs to be moved into a larger container with fresh mix around the roots. Take care not to damage the roots when transplanting, especially if they have gone through the drainage holes in the bottom of your pots!
Seedlings that are too leggy or tall have been grown without sufficient light, so the plant has stretched out reaching for it. Try to get the seedlings into a place where light is available for more hours per day. Tall tomato plants can be buried deeply when transferring into larger pots or when being moved out to the garden. Any buried stem will develop roots along its length.
Yellowed or sickly looking seedlings may need feeding or less watering. Allow the mix to dry out and then feed with a liquid food at diluted strength.
Seedlings that have been grown indoors need time to transition into the outside world. If possible, move the trays of young plants outside for some hours of daylight and then return them to the protection of the house at night. A selected spot should be out of direct wind or sun and preferably not likely to be soaked by heavy rain. After a week of this protected environment, the seedlings should be ready to be planted in the garden beds.
How to plant seedlings in the garden
Once the plants have been hardened off and the danger of frost is past (if applicable) take the seedlings and a full watering can out to the row or bed. Using the spacing chart provided in the next section, dig a small hole. Place the seedling in the ground at about the height it was growing in the pot (except tomatoes, which can be buried or laid on an angle). Press the earth down firmly and water well. Continue watering during the next few days. In some areas, cutworms are a problem. They will eat the seedling off at ground level during the night and then burrow into the ground to rest. Place a small strip (2” x 6”) of newspaper around the stem as a collar. This will decay into the soil but thwart the cutworms’ attack.
Plant seed and seedlings according to the following row spacing chart
if you are using rows in your vegetable garden. If your direct-sown seedlings come up too close together based on this chart, carefully pull out additional ones to achieve the desired spacing.
|4||Beets; Leaf Lettuce; Onions; Parsnips; Spinach; Turnips;|
|6||Beans (Bush); Collards; Celery; Mustard;|
|8||Beans (Pole); Beans (Lima); Head Lettuce; Kohlrabi; Rutabaga;|
|12||Cabbage; Kale; Sweet and Dent Corn;|
|18||Broccoli; Brussel Sprouts; Cauliflower; Cucumber; Eggplant; Okra; Peppers; Tomatoes;|
|48||Musk Melons; Squash (Summer and Winter); Zucchini;|
Other methods of setting out plants
Wide row planting – In this method, a bed approximately 30” wide is planted by broadcasting (scattering) the seed across it. This works well in salad gardens where a mix of small greens is harvested at a very immature stage. Harvesting may be done by thinning the bed; that is, pulling out some of the plants growing together in a cluster, or by use of a pair of scissors snipping here and there along the bed to obtain enough salad for the desired use. Larger vegetable drops such as cabbage can also be wide row planted using a staggered pattern of the rows and allowing the minimum row distance per plant between specimens in each direction. In the case of cabbage, this would be 12” on center in a diamond shaped pattern.
Raised beds – Instead of planting at ground level, the surface of the soil is raised above the walkways. Soil may be simply mounded up, or retained within artificial walls of concrete blocks, cut down wooden pallets, old timbers, etc. Make them a size that you can reach into without difficulty, for instance 4 ft. wide by 12 ft. long with access on all sides. Compost and other soil improvements are distributed inside the raised area, and the soil is never compacted by foot traffic. Set out plants in a grid pattern to take advantage of all useable space. These raised beds may be ideal for use by a gardener with mobility problems.
Container gardening – Ideal for gardeners in city environments or for patio gardens. Take extra large plant tubs or half whisky barrels and fill with a good quality garden or potting soil. Allow for good drainage so that roots do not become waterlogged. Seeds can be direct seeded into a barrel or transplanted from seedlings. Put taller plants towards the back so as not to overshadow smaller ones. Feed and water more often as roots are in competition in this limited space. Promptly remove any insect pests or diseased plants to avoid damage to the whole collection.
Water and feed regularly
Just as you fed and watered your seedlings in the house, they will continue to need attention in the garden. Perhaps it isn’t raining much this summer, and your plants are drooping in the early morning. This is a sure sign that watering is needed. Most plants will wilt in the hot afternoons of summer but recover overnight. If you are using a sprinkler system and hose, keep a rain gauge in the garden to ensure that all plants receive up to an inch. Do this once a week rather than watering daily in small amounts. Do not water in the midday or heat of the afternoon; too much will be lost to evaporation. Spread mulch around the plants to cool the soil and slow down drying. Use black plastic or grass clippings or compost. These will also choke out weeds.
Organic gardeners can feed their vegetables with liquid or dried fish and kelp products and regular side dressings of compost. Do not put manures directly on the garden plants as it is too strong and will damage or kill them. Non-organic gardeners can purchase chemical fertilizers in granular or liquid form and apply per the instructions, taking care not to touch the leaves or stems, as these are also concentrated products and can burn your plants.
Provide support to strong plants
Tall or vining plants such as pole beans, tomatoes, cucumbers, and peas will require staking or other means of support. Peas can be grown on discarded brush stuck in along the rows or on meshes or nets specially sold for the purpose. Tomato cages can be bought commercially but are often too small for heirloom varieties which can often grow to 6 or more feet in height. Install fence posts or lengths of galvanized wire in advance of the plants needing them so that you will be ready to tie up your sprawling vines before they set fruit.
How long till harvest?
The following table gives approximate days between planting in the garden and harvest. Note that plants which are set out as seedlings (tomatoes, peppers, eggplants, cabbage, broccoli, etc.) do not include the time spent growing indoors before setting out in the garden.
|Turnip Greens; Spinach; Mustard Greens; Lettuce (leaf); Onions (Green);||35-45 days|
|Kale; Swiss Chard; Kohlrabi; Beans (Bush and Wax); Beets; Lettuce (Head); Turnip; Amaranth (As a vegetable);||50-60 days|
|Cauliflower; Peas (English); Beans (Pole); Okra; Cucumber;||60-70 days|
|Broccoli; Carrot; Pepper; Cabbage; Chinese Cabbage; Sweet Corn; Lima Beans (Bush); Crowder Peas;||70-85 days|
|Watermelon; Collards; Cantaloupe; Tomato; Lima Beans (Pole); Eggplant; Endive; Summer Squash; Rutabaga;||80-90 days|
|Winter Squash; Onions (Dry); Tomatillo;||100 days|
|Potato; Celeriac; Pumpkins;||up to 120 days|
|Sweet Potato; Parsnips; Salsify;||150 days|
While there are commercial insect sprays available at all garden centers, most will have the disadvantage of also killing beneficial insects which are so important to the life of your garden. Rather than introduce these products to your eco-system, take time to look at the plants and discover if there is any damage and what might be the cause. The white cabbage butterfly can be seen flitting about between your cabbage plants in June. Just turn over the leaves and search out the newly laid egg clusters. Wipe them off with your fingers or a cloth and you have prevented damage from this pest. Look at potato leaves for the eggs of the Colorado Potato Beetle which is a small black and white striped insect. Caterpillars may be removed and crushed underfoot. Look for small piles of green “manure” on your plant leaves in the early morning and you will often find the caterpillar tucked under a shady leaf for the day. Tomato Hornworms can easily be detected simply by the amount of damage done in one night. Find this large pale green worm and dispatch him summarily underfoot or feed him to your chickens!
Pull weeds daily or at least while they are small. On no account should you let weeds go to seed in the garden, as your job next year will be that much harder. If at all possible be sure to pull the entire plant, including the root, as many weeds can re-grow from severed root stock if it is not all removed. Remember that a weed is any plant not growing in the desired location, so a volunteer tomato plant growing in your onion bed should be pulled out and discarded or transplanted into the tomato row.
In dormant places in the garden or after harvesting an early crop, sow a plant which will be dug back into the soil as an improvement. Examples of such “cover crops” or “green manures” would be alfalfa, buckwheat, Sudangrass, hairy vetch, annual rye grass, or a legume crop such as cow or field peas or soybeans. Broadcast seed widely over the area and allow the plants to come up thickly so as to choke weeds and provide a living canopy over the soil surface. Roto-till or scythe and then dig the residues into the ground to improve your soil organically by providing food for earthworms and much needed plant material (humus) in the soil’s composition. Sandy soils will hold moisture with more humus, and clay soils are aerated or broken down with addition of humus. Be sure to allow enough time for your cover crops to break down in the soil before replanting vegetables.
In one corner of every good garden there should be a compost pile ready to receive weeds and crop residues. Do not leave cabbage leaves, corn stalks, or other plant leavings standing in the garden as they will provide habitats for over-wintering insect pests and diseases. Either loosely stack plant material in a heap or purchase or make your own compost container. A length of open weave wire fence can be formed into a circle about 3 to 4 ft. across and preferably no higher than 3 ft. on the sides. To make compost you need three things: organic matter, air, and water. Damp down the layers as you build the pile with a hose or watering can. In dry periods water the entire pile if rain is not expected to fall. The pile should be damp but not saturated.
Your compost “circle” should be filled by alternating layers of organic matter: dry brown (carbon) and moist green (nitrogen) materials (for example, used hay or straw between layers of grass clippings and weeds). Do not make any layer more than 4” deep, or you may smother the pile so that it cannot break down properly and instead merely decays in a stinking mess. Allow air to circulate through the container and lay branches or poles through the pile which can be removed later to produce air channels. Add kitchen scraps but no meat, which will encourage raiding animals. Barnyard manure may be added in small quantities to the various layers, but please no dog, cat, or human wastes because of the danger of pathogens.
If possible turn the compost once during the summer season; that is, prepare another such “circle” or bin, and fork the full heap over into the empty one. This will speed up the breakdown of the material in the pile. If you cannot turn your compost, simply let it sit through one garden season and winter and use it next Spring. Shovelfuls can be dug into beds or placed around perennial plants as a top dressing or mulch. Note that compost is produced by the breaking down of plant residues and manure, and this break down will continue after you have added the compost to the soil – in other words, do as nature does and keep making more!
Harvesting – Deciding if your fruits and vegetables are ready to be eaten
Most vegetables are at their peak when harvested small. Young, tender carrots, for instance, taste much better than older, woody ones. If you are approaching the number of days to harvest for the variety, closely examine the crops and see if some specimens could not now be taken and enjoyed. Some plants have specific tests to see if they have reached maturity. For instance, a Hubbard squash is good for root cellar storage if the skin is tough. Try with your fingernail to make an impression in the skin. If you can’t, it is ready for long term storage. Cantaloupes are ripe for eating when gently sliding your thumb against the vine easily separates it from the melon. They also have a strong fruit odor. Watermelons are ready when they sound hollow or thud when you knock on them. Consult gardening books for other “Is it ready to eat?” tips.
Preserving your harvest
Canning – Preserve many garden products by canning in glass jars or tin cans. Some may be processed in boiling water baths while others must be canned in pressure cookers. The ultimate reference for canning is the Ball Blue Book, published by Alltrista Corp., Muncie, IN 47307-0729. Please consult modern tables for canning times and information as older material has been revised.
Root cellar – If your home has a basement, take one corner and build a root cellar. This should be an unheated area which can be kept dark and cool. Provide open rack shelving and slatted bins for storage of whole winter squash, onions, or potatoes. Provide a screened ventilation source and check the stored produce regularly to look for decay and signs of insect or mice damage. Put out traps if necessary, not poison, to protect your food supply.
Freezing – Many vegetables can be successfully frozen after a process known as blanching, in which the produce is immersed quickly into boiling water and then packed in plastic tubs or strong plastic bags.
Drying – Commercial, round, electric powered food dehydrators are readily available, often with additional drying racks. Many fruits and vegetables can be processed in this way and stored in a small space due to the reduction in bulk. Tomatoes for drying should be of the paste rather than beefsteak type. Dryers are ideal for preserving herb crops too. Weigh produce before drying and during the process to determine the percentage of water lost. Foods should be cooled and then stored in airtight containers when the required percentage of water has been driven off. See manufacturer’s directions. Solar dryers can be homemade, and home ovens can be used as dehydrators, too.
Saving seed for next year
If you want to save seed, there are several books available on the subject. You can learn how to keep plants pure so that their seeds run true-to-type, as growing parent plants properly is the key to producing good seed for subsequent years. As a very general rule for the beginning seed saver, note that any plant with the same Latin name as another plant has the ability to, and most likely will, cross pollinate. In layman’s terms, planting Hubbard True Green Squash (Cucurbita maxima) and Big Max pumpkins (also Cucurbita maxima) in the same garden means that you should not save seed from either as they are insect pollinated. In all likelihood, the bees that went to one plant’s flowers also went to the other one so you will have a crossed seed resulting. If the plants have different Latin names, like cucumbers (Cucumis sativus) and zucchini (Cucurbita pepo), they cannot cross. On the other hand, several varieties of self-pollinated plants like beans, peas, tomatoes, and lettuce can be grown together without too much fear of crossing. If in any doubt, please consult a book on this fascinating topic.
Having grown your vegetables for seed, select the best specimens from the best plants and let the fruit fully mature to ensure that the seed within is at its best, too. Cucumbers, for example, must be grown till well past their eating stage to grow seed useful for saving. Tomato, squash, pumpkin, melon, and cucumber seed all benefit from fermenting the seeds and the surrounding pulp for about three days before cleaning and then drying. The pulp should be put into a jar with a little water and shaken or stirred twice daily for three days. At the end of this time, the pulp and immature seeds will be floating on top as scum, and the mature and useful seeds will have sunk to the bottom. Take these and dry them on labeled paper plates for about two weeks before placing in a cool, dry place; for instance, in a bag or tub in the freezer, ready for planting next year.
Putting your garden to rest for the winter
Remove all crop residue and weeds from the entire garden and dump all in the compost bin. Anything left in the garden may harbor over-wintering insects which will be poised ready to attack your new crops in the Spring. If possible, plant the garden with a cover crop, especially annual ryegrass, before the first Winter frost. This will grow into a thick cover for the garden and protect the soil from erosion over the cold season. Otherwise, lay down a blanket of straw as mulch or even leaves collected in the Fall. These will cover the soil and break down before the next planting. Anything remaining in Spring can be raked up and put into the compost bin then.
Planning for next season
When planning locations of next year’s crops, rotate your rows or beds so that each vegetable is planted in a different location from what it was the previous year. Keep all your garden plans for a few years at a time to ensure you are holding to this rule.
Seed Starting Chart for Flowers
Follow the general seed starting directions above.
|Flower Variety||Weeks before last spring frost to start plants indoors|
|Pansies; Poppies; Snapdragons;||12|
|Marigolds; Zinnias; Nasturtium; Morning Glories;||4|
Planting and Growing Sunflowers
For giant-sized heads, space the plants at least three or four feet apart. Overcrowding will cause the plants to fall in heavy winds. In garden beds, the plants should be grown along a fence or property line. There are also dwarf and semi-dwarf varieties which may be grown in mixed flower beds. Some produce multiple flower heads on branching stems.
Planting and Growing Sweet Peas
These do best in cool summers and need cool moist weather to grow and flower well. Sow the seed outside as soon as the ground can be worked in Spring. Vining varieties, which may often reach 10 feet in height, should be planted about 3” apart and support provided. Bushy types should be planted with about 10” between plants. All types need to be repeatedly cut for bouquets as they will die once setting seed. Please note: plants, pods, and seeds of Sweet Pea flower are all poisonous.
Seed Starting Chart for Herbs
Follow the general seed starting directions above.
|Herb Variety||Weeks before last spring frost to start plants indoors|
|Chives (Garlic and Onion); Oregano; Yarrow; Parsley;||12-14|
|Thyme; Chamomile. Feverfew; Catnip;||8-12|
|Dill; Chervil; Coriander; Lemon Balm; Sage; Savory; Basil;||6-8|
Row Spacing Chart for Herb Plantings
Set out your herb seedlings according to the following chart:
|6||Anise; Caraway; Chervil; Chives; Marjoram; Parsley; Savory; Sesame; Shallot;|
|10||Basil; Hyssop; Thyme;|
|12||Burnet; Costmary; Dill; Mint; Oregano; Tarragon;|
|18||Fennel; Lemon Balm (Melissa officinalis); Rosemary; Sweet Cicely;|