Gardening with Gary

Gardening Advice from an Expert

Bulbs

Q. I've recently moved to Germany and in the winter it stays around the freezing
point. I planted Glads and Dahlias this summer and they are about finished blooming. Do I need to take the bulbs out or can I leave them in the ground? Also, I was given a potted Calla plant - all the blooms were cut off. Can I plant it in the ground now? What should I do over the winter?

A. For glads, dahlias and calla lilies, the rules are all the same. They are tender bulbs/corms/tubers which cannot take any temperature down near, at, or below freezing. You risk losing them all. If you have one brief cold snap, they will turn to mush. It is not worth the risk, plus it is very easy to overwinter them.

In the fall, as the cool temps arrive and before the ground gets cold, spade them up and allow to dry on papers inside, as in a dry dark, relatively cool spot like a basement. Be very careful to dig out away from their growth, as you do not want to split the underground growths. Then, shake and remove most of the soil and trim off the browned top foliage and the roots. Spread them out where they will be protected and not disturbed. Let them lay there over the winter and check periodically for any rotten ones which you discard.

Then, in the spring after your frost date has passed, you can replant outdoors in the garden beds. At that time, return to me and I will describe what I recommend in the procedure.

Since this is September, I do not recommend that you plant the calla into the ground, since you will need to be taking it inside very soon and knocking it out of the pot, but keep it green, watered and fed until then.

Q. I live in zone 6 and I just purchased 100 bulbs. I know nothing about planting them! I know it's too early [September 9th] and that the ground is still too warm, but that's all I know. How close do I plant them? When do I plant them? Do I feed them or cover with mulch?

A. I see from your questions that you are aware of the conditions. Plant the bulbs in the soil beds in about one month [October 1st]. They will benefit from getting settled before winter.

Dig down into the soil and emend it with some compost, leaf mold or dried leaves. Do not add fertilizer.

Set them down about 4-5" deep with the pointed part up, about 6-9" apart. You can plant closely to make bunches of flowers, or farther apart to have each one separate. It is according to your wishes.

Water in well and yes, you can mulch one inch on top to keep them protected through the cold. It serves as a good protection.

In the spring, you will see new growth pop up. Give them a quick shot of fertilizer to help them on their way. After blooming, maintain the green foliage to build up the bulbs with food production from the leaves. Water well, and stake the leaves if they are in the way of later flowers, as annuals, in your beds.

Forcing Bulbs in Refrigerator:

Q. How long do you leave the bulbs in the refrigerator to simulate the cold season? Is it 8 weeks? Thanks so much.

A. Here is a write-up on forcing bulbs in a refrigerator. I feel it has all the info you need. It is great fun doing this, fooling Mother Nature and having color inside when the snow is on the ground outside!

Spring-blooming bulbs such as tulips, daffodils, crocuses and hyacinths can be forced with the help of your refrigerator, giving you the chance to enjoy a hint of spring in the middle of winter. You'll need clay pots small enough to fit into the vegetable crisper of your refrigerator.

Fill the pots half full of good potting soil. Set the bulbs in the potting mix, pointed ends up and side by side, as close together as possible. Cover the bulbs with potting soil to within 1" of the rim of the pot.

Label the pots with the types of bulbs used and the date planted. Place the potted bulbs in the vegetable crisper of the refrigerator. Don't store fruit and vegetables in the crisper at the same time: they give off ethylene gas that may damage the bulbs.

After the appropriate period of chilling (for tulips, eight to 10 weeks; daffodils, 12 to 14 weeks; small bulbs such as crocuses, grape hyacinths and freesias, four to six weeks), bring pots indoors to a cool, sunny room, ideally at a temperature of 55 to 65 degrees. Warmer temperatures may cause the plants to have weak stems. Even if the bulbs seem to be growing rapidly, chill them a minimum of four weeks. Well-developed roots will show through the drain hole at the bottom of the pot. Stagger removing the pots from the refrigerator so you can enjoy a longer period of bloom.

Once the pots have been removed from the fridge, keep the soil moist, and give the pots a one-quarter turn every day to keep the stems straight as the plants turn toward the light. After the plants have finished blooming, you can discard and compost the spent bulbs or plant them outside, giving them a dose of fertilizer once they're in the ground.

If you'd like to plant the bulbs you forced outside instead of putting them in the compost, remove the faded flowers, cutting them off near the base. Leave the leaves on, and plant the plant in the ground outdoors. Then fertilize and water it to keep the leaves green and healthy as long as you can, stopping only once the tops begin to dry.

Source: Do It Yourself Network

Member Judy writes~
I just bought some bulbs which I want to force in January or so. How long do they need to be in the refrigerator to simulate the cold season? They are daffodils and hyacinths.

A. Forcing is a process by which plants are stimulated to bloom at other than their normal time. Bringing hardy bulbs indoors will add color to household plants. This is easily accomplished with hardy bulbs if there is storage for the bulbs at a cold temperature.

Many spring bulbs can be forced indoors. Of the many types of tulips available, the Triumph strain is best because they have short, thick, sturdy stems. Other tulips will bloom indoors but may have weak, long stems and look out of proportion to their container.

Plant bulbs for forcing in a clean container with a drainage hole, in a loose potting soil, such as six of one part humus, one, part peat or vermiculite and one part sand or perlite. Position each bulb so that its top is even with the top edge of the container. Plant several bulbs in a container for best display.

After planting, water the pots thoroughly and label each pot with the planting date and bulb variety. Fertilizer is not needed as the bulb has all the stored food within itself that will be needed to flower. Store the bulbs at least 13 weeks at temperatures between 35 and 48 degrees F and can be stored for longer, but not for less time. The storage period is critical to developing good roots; if the root system is underdeveloped, the flowers will be small and floppy. Good storage areas may be difficult to find; some possibilities include unheated cellars, porches, cold frames or even the refrigerator. The bulbs can even be buried in the garden and covered with a thick layer of straw to keep the ground unfrozen.

When the desired flowering time is early January, the approximate planting time is early September. When the desired flowering time is February, the approximate planting time is October and when the desired flowering time is March-April, the approximate planting time is Mid-November. After 13 Weeks, bring the pots indoors into a sunny room with temperatures around 60 degrees F. Warmer temperatures are undesirable, as they encourage rapid growth of long, lanky stems and foliage. The bulbs should be kept moist. The flowers should open in three to four weeks.

During flowering, it is advisable to keep the plants in as cool an area as possible, and keep the plants moist to encourage longer blooming. After flowering, the bulbs may be disposed of, as most will not flower well again. Exceptions are the hyacinth and daffodils, which may flower again if planted outdoors. When saving the bulbs, fertilize the plants with a high phosphorous houseplant fertilizer to keep them moist and to encourage healthy green leaves for the longest period of time. If possible, plant the bulbs in the spring after their foliage has died down, at their normal depth in the garden - about 6 inches deep for large bulbs and 2 to 3 inches deep for smaller bulbs.

From: "Forcing Bulbs Indoors" by Nancy J. Butler
MSU [my alma mater!] Cooperative Extension Service
Weed'Em and Reap-Aug.-Sept. 1987

For recommended varieties for forcing, go to:
http://www.msue.msu.edu/msue/imp/mod03/03900011.html

Q. It is becoming a little nippy here [September 5] in zone five. Right now it
is about 60F and the highs get into the middle 70's. How do I rest my bulbs? I heard that you dig up all the foliage and the bulb and let dry. Wouldn't that take away from the energy?

A. I do not know which bulbs you are referring to. All the plants should sit in the garden beds until fall, when the foliage has begun to dry and turn brown. If any of your plants still have green foliage, keep watering them until they decide to rest. The temps you cited are still quite high. Wait until the night temps drop into the consistently low 50Fs. Spring-flowering bulbs stay in the ground all winter, or they will not induce flower sets for next spring. Summer-flowering bulbs must be dug up for winter protection in your zone.

In a few weeks, you can start digging up those bulbs which have no green leaves. Lay them out on newspaper and allow to dry in a cool, dark, dry spot as a basement, undisturbed. When dried, knock off any soil and cut the foliage right back to the top of the bulb. Lay bulbs out in a clean area or hang in mesh bags for air circulation. Then, come spring, you can plant them again after sorting out any weak, mushy dry bulbs.

Q. We drove past a yard last April which was filled with colorful flowers. How did they do that and does it hurt your lawn?

A. Early flowering spring bulbs may be planted in the fall [September to October] right into your lawn. They pop up in the late winter right through the grass. It is best to plant quite a few of them, as it takes many to put
on a show. But they do not cost that much.

After they have finished blooming, mow the lawn as usual. The grass does not need attention until they are finished with their show. Most, but not all, will come up the next year for a repeat.

Here are some bulbs to look for this fall and plant, at a depth of 2", no deeper:

Spring crocus
Snowdrop
Snowflake
Squill
Grape hyacinth
Chionodoxa

M & K write~
My son is getting into indoor gardening and has two questions. We had bought paper white bulbs and miniature amaryllis bulbs before Christmas. Flowered beautifully. Now what do we do? Save bulbs? Throw away plant? There are seed caps on top of amaryllis. Same with crocuses and hyacinth. Bought these as plants about to bloom from grocery. Bloomed beautifully. Now finished. What do we do with plant/bulbs? Save? Plant in garden in spring? (we live in northwestern Canada)

A. I am pleased that the interest in gardening is developing. I started gardening indoors and outside when I was 12 and never looked back. I knew right away that Horticulture was a big interest and continued through college.

For the amaryllis:

Keep the foliage growing and green as long as you can. Give good water as needed when dry and feed them with a dilute fertilizer for house plants. This will build up the bulbs as the foliage produces food for underground. If you do not allow this process to continue, the bulbs will be burnt out and die.

You can then plant them outside in the spring, when the frost danger is gone. Nurse them all summer and then allow the foliage to die back. Dig up bulbs, plant in clean pots and new soil and force inside during the winter to bloom once again. Or, save them over the winter, plant outdoors and have them bloom outside in the summer.

Same with crocuses and hyacinths. Any spring-flowering bulbs which you buy either in bloom or getting ready to bloom need to be maintained for food production. Then, plant them outdoors and encourage summer growth. There is no need to toss away bloomed-out bulbs. Just keep them going and they will continue to bring pleasure again and again with food, water and sunlight!

Shelley writes~ I have tulips and daffodils planted in my yard. I have been told that every three years you are supposed to dig these bulbs up and separate them in order to keep them flowering. Is this true? If so, is it best to do this in the spring or fall? And finally, how many bulbs should be planted together in the cluster when you plant or replant these types of bulbs?

A. Certain bulbs need dividing or separating in order to maintain a healthy, flowering stand. Crowded bulbs are less likely to produce a high quantity and quality flowers. When flower number and size starts to diminish, consider separating the bulbs and replant.

Bulbs planted at recommended depths initially require less dividing and resetting. Spring flowering bulbs such as daffodils, tulips and hyacinths should be divided in September or October. Granted, it is difficult to determine the location of the bulbs without staking or mapping them out previously. Care should be taken when digging to prevent damage to bulbs. It usually is easier to dig a large area and separate bulbs then trying to dig individual bulbs separately.

If bulbs are planted among trees, shrubs or perennials, consider replacing the bulbs every three to five years instead of separating. This minimizes damage to the root system of the nearby plants.

Summer flowering bulbs can be divided in early April or late fall. Some bulbs, including Surprise Lilies (Autumn Lycoris) may not appear to need dividing. However, plants will produce more flowers if divided.

When dividing or separating bulbs, carefully remove side bulbs from the main bulb. Replant at correct spacing.

The following table provides a guideline for dividing bulbs: Bulb Years to Divide Tulips 3 - 5 Daffodils 3 - 6 Hyacinths 2 - 3 Lilies 4 - 6 Surprise Lily (Lycoris) 3 - 5 Iris (Bulbous types) 3 - 6 Alliums 4 - 8 Crocus seldom needed Grape Hyacinths (Muscari) seldom needed

Copyright 1995 by the Board of Trustees of the University of Illinois.

As to clumping, you do not have to plant your bulbs in this fashion. But, if you like a bunch of flowers in one location, plant the bulbs or corms 5 per spot, at a distance of 6-8" apart. When they flower, you will have a clump of bloom, instead of individuals as in a row or border. This presents a fine, naturalized appearance.

Be sure to work up the flower beds and supplement with organic material to furnish nutrients. Remove old, dead bulbs, foliage and stems to prevent spread of disease. Consider adding some bone meal at this time.

Karen writes~
I received a couple Hyacinths and Tulips for Easter and now that the flowers have bloomed, when is the best time to replant them for next year? Any tips on dividing up and replanting some from a few years ago and Daffodils also. What about dividing Lily of the Valley plants and when is best to plant them?

A. The first part of your question has been answered and will be on my website within a week or two, but separating early spring flowering bulbs is a chore for the Fall.

As for the lilies, they are the kind of plants which are divided by separating their tubers or rhizomes, including: Banana, Elephant Ear, Canna, Caladium, Anemone, Tuberous Begonias, Bleeding Heart, Cyclamen, Dahlia, Gloxinia, Bird of Paradise, Calla Lily, Iris, Lily of the Valley, Mint, Rhubarb, Yams and Potatoes.

This should never be done before or during flowering and the foliage should be allowed to grow and produce food for the underground growths. In the late summer to early fall, dig up the lilies and separate the rhizomes, replant in a good soil with organic material and a slow release fertilizer if desired. Water well and allow to overwinter undisturbed. By spacing them out, you can turn one plant into a nice bed within a few years!