There is great satisfaction when you start your garden from seed. Watching your plants grow from seedling to harvest-ready is wonderful but it can be a very frustrating period if things don’t go as planned. We have a few tips if you want to start your garden from seed so your garden turns out just how you wanted.
There are 3 main things to know about starting seeds;
Plant your seeds in a very well-drained seedling potting mix. If you will be making your own soil mixture, be sure to add enough fluffy matter (ie: Vermiculite, Perlite, or Peat Moss) to keep the soil from getting too dense or water-logged while the seeds are still developing.
Perhaps the most difficult part of starting seeds is providing enough light. You do not want to burn the seeds but want to give enough light for them to grow. If possible, start your seeds in a warm room or (non-drafty) window area with at least 6 hours of direct sunlight per day. If you need to supplement your existing light, use a plant grow light, which can be found at most hardware stores.
The soil used for germinating your seeds should be kept evenly moist but not soaking wet. Too much moisture will cause the seeds to rot. Using a fine mist sprayer or watering from the bottom are great methods.
TIMES TO SOW SEEDS INDOORS:
January pansies, violas, begonia bulbs
Early Feb geraniums, hardy herbs (parsley, thyme, lavender, etc.), dusty miller
Late February snapdragons, impatiens, gazanias, dianthus, take cuttings of fuchsia and geraniums
March petunias, ageratum, salvia, dwarf zinnias & marigolds, alyssum, verbena, seed dahlias, peppers, part of cabbage crop, cuttings of impatiens
Early April zinnias, lobelia, large marigolds, asters
Mid April tomatoes, rest of cabbage crop, annual herbs (dill, basil, etc.), large zinnias, eggplant
Late April/Early May cantaloupe, squash, pumpkins, cucumbers, watermelons, lettuce, spinach
June cabbage, broccoli, cauliflower for fall crops
TIMES TO SOW OR PLANT OUTDOORS:
March 15th pea seed, potato eyes, onion sets
April 15th Set out-strawberry roots, asparagus roots
Seed-broccoli, carrots, kohlrabi, radishes, lettuce, spinach
Plant out-reg & Chinese cabbage, bunch onions, kohlrabi, swiss chard, wildflower seeds
Plant hardy lily bulbs and lily-of-the-valley pips
Transplant hardened off pansies, violas, and primrose plants
April 23rd Set out plants-beets, broccoli, Brussels sprouts, cauliflower, carrots, strawberries, hardy herbs. Set out-perennial plants, rhubarb, all nursery stock, plant-gladiolas and freesia bulbs, transplant-hardened off alyssum and snapdragons
May 1st Seed-corn, beans, squash, pumpkin, lettuce, transplant-lettuce, spinach, chard plants
May 15th Transplant-tomatoes, peppers, cucumbers, melons, eggplant, peanuts, okra, artichokes, pumpkin plants, plant out-begonia, caladium, canna bulbs and container roses
In general, it is safe to plant everything after May 15th. If long cold periods arrive in the spring time, cover your plants with a blanket to avoid frost damage
Nearly half of the general listed bulbs in the A-Z guide, are true bulbs. The onion represents the basic structure of this type of bulbous plant. The pear-shaped or oval bulb is a complete plant in miniature. At the heart of the bulb is the embryonic flower surrounded by the undeveloped shoot, and the body of the bulb is made up of a series of fleshy scales. These scales are modified leaves held together by the basal plate at the bottom — the scales contain the nutrients which sustain the plant during the dormant period and the first stages of growth. With most true bulbs the scales are closely packed together but with some types, such as the Lily, they are loose and swollen. Most popular bulbs have a papery skin, the purpose of this tunic is to protect the tissues within. Some true bulbs such as the Lily do not have a tunic and are therefore easily damaged by rough handling. Cardiorinum dies after flowering but other bulbs are perennial. Reproduction is by means of offsets (bulblets).
Examples: Muscari, Tulipa, Narcissus, Lilium, Allium.
Some corms look like bulbs. Many but not all of these rounded or flattened bulbous plants have a protective smooth or fibrous tunic, and there is the true bulb pattern of a central growing point or two at the top and a basal plate from which the roots arise at the bottom. The structure of a corm, however, is fundamentally different. The nutrient-holding body is a stem base and not a series of scales, and the tunic is made up of the dry leaf bases from the previous season. Another important difference is that a corm lasts just one year. When active growth is underway the food store is depleted and the corm starts to shrivel. At the same time one or more new corms start to develop on top or at the sides of the old one. These new corms form next year’s planting material and will flower during the season. A few corms such as Gladioli form small cormlets around the edge, these tiny corms take 2 to 3 years before they reach the flowering stage.
Examples: Crocus, Gladiolus, Freesia, Ixia, Acidanthera.
A tuber is a swollen stem which is born underground like a corm, but the similarity ends there. A tuber does not have a basal plate nor is there a protective fibrous covering. There is no neat organization of the growing points — a potato has the classic arrangement of a tuber. The buds or eyes are scattered over the surface and so stems appear from the sides as well as the top of the structure. There is no standard shape, but they are usually squat and knobby. Most types of tuber get bigger as the plant grows but others diminish in size.
Examples: Cyclamen, Gloriosa, Anemone, Eranthis, Begonia.
The rhizome, corm and tuber are all bulbous types which are thickened stems filled with nutrients to support the growing plant. Rhizomes differ from the others by growing horizontally and spreading outwards either partly or completely below the soil surface. The main growing point is at the tip of the rhizome, but other buds are formed along the upper surface and along the sides. Roots develop from buds on the underside of the rhizome. Most rhizomes are easy to propagate as the long and branching stem can be cut into segments for planting — make sure each piece has roots and at least one bud.
Examples: Convallaria, Canna, Achimenes, Zantedeschia, Agapanthus.
This bulbous type differs from all the others by being a swollen root rather than a swollen stem or a collection of scale leaves. There are several alternative names — root tuber, tuber-like root, etc. Dahlia is a typical example and is the best known tuberous root. The swollen storage organs are born as a cluster from the crown, which is the base of the old stems. These modified roots provide stored nutrients to the plant — during growth fibrous roots are produced to absorb water and nutrients from the soil. The bulbous plants can be propagated by cutting off individual storage roots with a bud (eye) bearing section at the top.
Examples: Dahlia, Eremurus, Clivia, Alstroemeria, Ranunculus.
The pseudobulb is a specialized storage organ which is produced by many Orchids. It is a thickened stem base and unlike the other bulbous types on this page, the pseudobulb is both green and above ground. It may be oval, cylindrical, or globular and from it arise both leaves and flower stalk.
Examples: Bletilla, Pleione.
Fall Bulbs: planted in the Fall (Sept. & Oct.) because they need a cold treatment to bloom.
*they bloom mostly in the Spring.
Spring Bulbs: planted in the Spring, not winter hardy, bloom in the Summer.
Indoor Bulbs: plant in Winter/early Spring; Paper White Narcissus, Amaryllis.
Planting Fall Bulbs
Depth: the hole should be 3-4 times the height of the bulb.
Soil: well drained, add peat moss, loosen the soil in the whole area.
Fertilize with bonemeal, phosphate or bulb food; work it into the soil to avoid burning the roots, and water well.
Site: Bulbs prefer sunny locations. Southern exposures will bloom before northern exposures, and may result in early emergence and freezing injury. Put earliest bloomers next to a window, solid colors are best viewed from distances, good drainage is key.
Post bloom care: cut off old blooms so seed pods don’t develop, leave leaves to rejuvenate bulbs, fertilize and water after bulbs finish blooming.
Mulch the bulbs about 3 inches in height and remove in April.
Spring Vs Summer Bulbs
The first thing to know about bulbs is the difference between spring flowering and summer flowering bulbs.
Spring flowering bulbs are the bulbs you see blooming in the spring, such as tulips, daffodils, crocus, etc. Summer flowering bulbs bloom much later in the season and include such beauties as; lilies, gladiolus, and some iris varieties.
Spring flowering bulbs are winter hardy; they are planted in the fall and after blooming in the spring, lie dormant until the next spring. They do not need to be dug out of the ground or stored, except when they need to be divided.
Some varieties of spring flowering bulbs are not winter hardy. They may need to be dug from the ground and stored in a frost-free area over the winter (this could be a garage or basement, etc.) until they are replanted the following spring. Please ask one of our garden experts if you are unsure which bulbs need to be dug up and stored.
Summer Bulbs must be dug up in the fall before ground freezes if they are to be saved for next season. Or you can treat them like an annual.
You plant summer bulbs in the spring, the best rule in Colorado to plant summer bulbs is: Start bulb inside by April 15th and plant it outside by May 15th.
Here are some varieties of summer bulbs: anemone, begonia, caladium , calla lily, canna, chlindanthus, dahlia, eucomia, freesia, gladiolus, daffodil, ranunculus.
When forcing bulbs, you are “convincing “ them that they have spent the winter underground outside.
- Use a shallow pot and well-drained soil.
- Most bulbs can be used. Crocus are the best of the small bulbs.
- Keep away slugs and other humidity loving pests.
- Plant from Mid-September until Mid-February.
- Plant just below the soil surface and water, no fertilizer is necessary.
- Store pots on the north side of a building or in an unheated garage or shed with a consistent temp.
- Indoors in the refrigerator is ok. The average temperature should be 40-50 degrees F.
- Hyacinths and crocus take about 10 weeks.
- At the end of their cold treatment, you should see roots coming out of the bottom of the pot.
- Remove from cold treatment and place in a cool room (60 degrees F) and indirect light for 2-3 days; shoots should appear.
- Move to a warmer room and full sun. It will take about 2 weeks for the blooms to appear.
- Cooler temperatures after the buds appear will make the blossoms last longer.
- Stagger planting for blooms all winter.
- Bulbs can be planted outside in the spring after the danger of frost is gone but may not perform as well.
Dividing your Bulbs
- Divide in Fall at planting time
- For best results, divide only when crowded
- Most bulblets will not bloom the first year, Iris need a new ‘eye’ to bloom
Care of Spring Bulbs
Harvest: after the leaves have died or first frost, except for Tuberous Begonias.
Do not bruise or scrape when digging the bulbs.
Leave the soil on the bulbs and dry before storing. Once dry gently break soil away from bulb but do not wash.
Storage: dust bulb with fungicide and insecticide (Dusting Sulfur).
Keep in a cool and dry place, 35-55 degrees F with peat moss or sawdust.
Check periodically; remove and discard rotted or extremely soft bulbs.
For most species listed, the curing period should be relatively short (e.g. dahlias, cannas, calla, caladium). This short-term curing period or drying period should be 1 to 3 days, depending somewhat on temperature. It should be done in a room or area away from direct sunlight or drying winds. For long term’ curing, as with gladiolus, tigridia, montbretia, and oxalis, the curing period should be approximately 3 weeks. Then, in the case of gladiolus, the old corms and cormels should be removed. Drying and curing temperatures for such materials should be 60-70 degrees in a dry, well-ventilated area.
Before storing corms, dust them with a fungicide-insecticide mixture, such as dusting sulfur. This will control thrips and protect small cuts from letting in rot.
One of the most important items to remember before placing the bulbs in storage is to label the plant material carefully. In the case of gladiolus and similar bulbs, this is easily handled by placing the corm in a small paper bag which has been labeled. Larger materials, like the fleshy rhizome of canna, can be handled in several ways. One technique that works quite well is to write directly on the fleshy root with a permanent felt marking pen. If this is done on large clumps the variety name should be written on several roots rather than on just one, because in storage occasionally a root is broken off of the main clump. “Tree labels” of the wood-and-wire type work well for labeling this type of plant bulb. In all cases, variety name and/or other important identifying characteristics should be written on the label and also recorded in a notebook. Labeling is not emphasized adequately in many cases, and many prized plants have been lost because of poor labeling.
Remember to periodically check your stored bulbs, tubers, and roots during the storage season. Remove any damaged or rotting materials and in cases where tuberous roots like dahlias have some rot occurring, cut back until you reach clean white, fleshy tissue again. Remember that these structures are living plants and as such need attention and care even during their dormant period.