Spring Flowering Bulb Basics

A Guarantee to the End of Winters Grip

Fertilization

A spring flowering bulb is a "complete" plant all by itself with everything it needs to perform the task at hand. However, it is still a good idea to incorporate some additional "bulb food" into the planting soil prior to planting your bulbs. An ideal food will be high in phosphorus and low in nitrogen. Bone meal at one time was considered the standard food to place around bulbs of all types and is still a standard component of many organic mixes. However, research has proven that bulbs respond better with a more "complete" mix of nutrients. If you plan on using Bone meal as a plant food, make it a part of a mix of nutrients rather than a "stand alone" food. Incorporate the bulb food into the bottom of the planting hole prior to placing the bulbs. Once the new growth begins in the spring, incorporate additional fertilizer into the soil around the plants to help them build strength for the coming years growth. Avoid fertilizing your bulbs once blooming begins to avoid the tendency to rot some bulbs and shorten the life of the flowers.

Check the soils pH prior to planting and yearly in the spring. The optimum pH level is between 6.0 and 7.0. Add lime to raise the pH and sulfur to lower it as necessary.

Planting Location

Familiarize yourself with the light requirements of the plant before you choose a location in your landscape. Many early spring bulbs bloom before the trees leaf out fully so planting beneath them poses no problem as to shade. However many late or summer bloomers will require full sun or partial shade in order to perform well.

Consider also that spring bulbs planted with a southerly exposure will bloom earlier than those planted with a northerly exposure as well as those planted higher up on a hill will also bloom sooner than those planted down in a valley.

Planting Depth

The general rule of thumb for planting spring bulbs is to plant them two to three times as deep as the bulb is tall. So following this thought, tulips or daffodils would be planted approximately 6" deep, but smaller bulbs would be 3" to 4" deep or less (see chart). This measurement is from the surface of the soil to the top of the bulb or corm proper (the shoulders). Spacing's are generally measured from center to center of the bulbs and plants.

The two basic methods of planting bulbs is to either dig individual holes or to excavate an area for mass plantings. For individual holes a bulb planter or auger is preferred, but a trowel can also be used effectively. For larger areas to be planted, as in mass plantings, a square-nosed shovel will work well. In either case, dig the hole slightly deeper than needed and back-fill accordingly with loose soil. Once your bulbs are placed, gently back-fill the hole with loose soil, being careful not to knock any bulbs over. Using your fingers, gently firm the soil around the bulbs to eliminate any air pockets and firm the soil.

Which End Is Up ?

With most bulbs "up" is not to difficult to determine, as most like tulips and daffodils will have a pointed end and a flat side. The pointed end is the end from which the leaves will emerge and should always be pointed up. Corms, tubers and rhizomes however do not posses such growing tips. In this case, you will need to look for the growing "nodes" that will sprout new leaves. This will determine the "up side". But with some of the smaller bulbs such as Anemones, which will resemble "dried peas" the direction is not critical and they will tend to find their own way to the sun.

Spread and Spacing

In every case of planting bulbs, their real beauty is in numbers. Always plant as many as you can in a given area to provide the greatest effect. Always try to plant in massed beds and not in geometrically correct lines. Bulb spacing is determined by bulb diameter and is generally 2 to 3 times the diameter of the bulb (see chart). However, for naturalizing this spacing will vary widely, as the purpose of naturalizing is to mimic nature. When naturalizing for the most natural effect, try this method for spacing and placement. Place the bulbs to be planted in a 5 gallon bucket and then aiming in the direction you wish them to grow, give them a gentle toss as if you were throwing out water. Plant each bulb where it lands. This will give you a more natural effect as in a meadow or glen.

Watering

After planting, water the bulbs well to settle the soil and provide them with moisture to start forming roots. Remember that your bulbs must get their root growth accomplished before the ground freezes. Avoid over watering, as bulbs have a tendency to rot if kept to wet.

In the spring, supplemental watering should not be needed unless you experience hot, dry weather. If this occurs, deep soak the bulbs weekly with at least an inch of water to provide longer lasting blooms either by rain or hose. In order to avoid splashing soil onto the plants use a soaker hose. Avoid over watering as some bulbs will rot quickly in the heat of summer.

Foliage Care

One of the biggest complaints about any bulbs is that the foliage remains after the blooms are gone and looks unsightly. All to often the temptation is to cut the foliage back or tie it up to improve the view. Sadly, those who do this would be better off to dig the bulbs and toss them out because they are condemning the bulbs to a slow, declining death. After flowering, the bulbs depend on the remaining foliage to build strength in the bulb for the following year. Without it, the bulbs slowly decline, stop producing and eventually die. The foliage on all bulbs should be left alone until it turns yellow and dies on its own. Avoid the temptation to "tie up" the foliage also because in doing so you seriously limit the amount of sunlight to the plant and consequently have the same effect as cutting it back.

Savvy gardeners have over the years learned tricks to draw attention away from the unsightly foliage. One way is to interplant the bulbs with other perennials like Hostas, that will come up and hide the foliage. Another way is to plant them behind other perennials along a border or other areas so that the perennials will come up and act as a screen. One gardener I knew even went so far as to install small trellises in front of each grouping of bulbs and planted little splashes of vertical color throughout his garden with vines such as morning glory and annual sweet peas. Use your imagination to hide the foliage, but don't cut it off.

Staking

Most spring-flowering bulbs dot need any additional support. However, if you plant summer bloomers such as Gladiolas, tall Alliums and Dahlias, these will greatly benefit from the extra support. If you do choose to support any plant, always put the stake in first before you plant to avoid damaging the bulb, corm or tuber. Never tie the plant. Rather use some form of support ring or hooked stake to keep it upright.

Mulching

An organic mulch of leaves or dried grass clippings is of definite benefit to bulbs and all garden plants. It serves to retain moisture, hold down weed growth and reduces soil from being splashed on the plants as well as breaking down into valuable organic matter to build up the soil. Avoid placing the mulch up tight around the plants though to allow air to circulate around the stems and help control disease and stem rot. Leave it away from the stems 2" or 3 inches.

After Blooming

The purpose of all blooms is reproduction of the species by setting seed. When blooms fade energy is diverted from the plant to form the seed. For this reason it is for the benefit of the bulbs to remove all spent and/or fading blooms so that all of the plants energies will be put back into the bulb. For the sake of sanitation to eliminate a potential source of disease, remove the petals from the ground as well as these are a prime breeding ground for disease organisms.

Unless the bulbs are not hardy where you live, most bulbs do not like to be disturbed and do not require digging. But be aware of the fact that healthy bulbs will multiply and divide readily on their own. If not periodically dug and divided, to many bulbs will occupy a given area and will become less vigorous, with fewer and smaller flowers. If this happens, plan on digging and dividing them. To avoid overcrowding outright, plan on digging and dividing your bulbs about every third or fourth year.

To know the proper time to dig your bulbs, bear in mind their life-cycle. In the spring after blooming, the leaves will continue to grow and nourish the bulbs. At the end of end of this growth cycle, the leaves will die down and the roots will also die. this is the time of dormancy for the bulbs until fall when the roots will start to grow again to provide the bulb with moisture and nourishment for the next years growth. It is at the end of this growing period, when dormancy begins that you should dig your bulbs.

When you dig your spring bulbs, store them in a cool, dry place until fall when it is time to replant them again except for daffodils and crocus, which should be replanted immediately.

For summer flowering bulbs that are not hardy, dig them just before a freeze kills the foliage and store them in a single layer in a well ventilated, frost-free area until they are dry but leave the leaves on the bulb until dry, then the leaves can be removed without damaging the bulb. This drying process should take between 1 to 2 weeks, at which time they will be ready to prepare them for storage.

To prepare your bulbs for storage, remove any remaining foliage and carefully remove any remaining soil. To remove the soil, gently shake off what you can and then carefully remove remainder by hand. Be careful to not damage the papery covering if possible. Then place the bulbs in unsealed paper bags and dust them with a fungicide powder to prevent rot. Store these away from sunlight in a cool, dry basement, cellar or garage at 60° to 65° F. Avoid temperatures below 50° F or above 70° unless you are provided with different instructions for a particular species. Tender Dahlias and Begonias will come with specific instructions for the particular species.

Number of Bulbs To Buy

There's beauty in numbers when it comes to spring bulbs. Use the following chart as a general guide to how many bulbs to buy for best visual effect in mass plantings.
 

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