The term allium typically refers to several bulb plants that include various types of onions and garlic, but when the term is used in gardening circles, it usually refers to inedible plants belonging to the genus. Allium bulbs are low maintenance, have flamboyant flowers, and tend to deter pests, and for these reasons they are a great addition to most gardens.
Steps
Method 1 of 3: Part One: Outdoor Growing
Step 1. Plant bulbs in the fall
Plant allium bulbs once the plants start shedding their leaves. You can usually plant them on any date between late September and late November, as long as the ground has not yet frozen.
The roots tend to form in the fall. You may also notice some buds in the fall if you live in warmer climates, but most stems and buds form in the spring
Step 2. Choose a good location
Allium plants love the sun, so they thrive best when planted in a flower bed that gets full sun - six hours or more of direct sunlight. The soil can be of medium nutritional quality, but it must drain well.
- Most plants of the genus allium can also grow in partial sun or in slightly shaded places, but the stems may become weaker in less light and therefore would not be able to support the weight of the flowers when the plants bloom.
- To determine if the soil is draining well, check it after heavy rainfall. If puddles are seen five to six hours after the last drop of rain, the soil is too compact and does not drain properly.
Step 3. Amend the soil as needed
Starting with well-draining soil will make things easier for you, however you can also amend the soil to improve its drainage capacity. Mix 5 to 7.5 cm of organic material such as peat moss, compost, earth bark, or decomposed manure.
- Mix this material with the soil by digging it 30 to 45 cm to make sure the drainage near the bulb is optimal.
- As a rule, it is not necessary to modify the soil to add nutritional content. Allium bulbs can grow in soil with poor nutritional quality, but they tend to rot in soils soaked in water.
Step 4. Dig holes deep enough
Dig a hole about two to three times the diameter of the bulb deep. It may seem overwhelming, but bulbs thrive best when planted deep and tend to weaken if planted too close to the soil surface.
- When planting multiple allium bulbs, you need to arrange them 15-20cm apart.
- Consider placing a 5cm layer of agricultural grit or inert compost at the bottom of the hole before placing the bulb inside. This way you can improve the drainage conditions.
Step 5. Plant the bulbs with the pointed end facing up
The stem will in fact develop from the pointed end, so this must be positioned upwards when you place the bulb in the ground.
Step 6. Press them
To ensure that the bulbs are well fed and protected, the amount of air pockets in the soil must be minimized. So use your hands and feet to compact the soil above the bulb, pressing as hard as possible.
Step 7. Water well
Add enough water to completely moisten the soil. It needs to be saturated with water and heavier in order to settle around the bulb.
Method 2 of 3: Part Two: Pot Growing
Step 1. Also in this case it is necessary to plant in autumn
Regardless of whether you keep the pots indoors or outdoors, you should still plant the bulbs in the fall as soon as you notice the leaves falling from the trees in your neighborhood. Planting in the fall allows the bulbs to develop roots and makes it easier for them to follow their natural growth cycle.
It is advisable to keep the pots in a cool place during the winter. Allium bulbs really thrive when they have a chance to cool down during the dormant season. You don't have to keep the pots outdoors, but storing them in a garage, basement, underground root warehouse, or shed is your best bet
Step 2. Choose large pots with drainage holes
The pot you use should be about five to six times deeper than the diameter of the bulb. It should also be wide enough to allow 6 inches of free space between the bulb and all sides of the container.
There should be at least four decent sized drainage holes in the bottom of the pot. Use a drill to make holes if necessary. Allium Bulbs will rot if forced to stay in soaked soil
Step 3. Fill the pot with good soil
Most commercial potting compost works quite well, but you should choose one that is light enough over ones that feel heavier and denser to the touch.
Keep in mind that allium bulbs don't have a lot of nutritional needs, but they do need well-draining soil. Dense soils that retain moisture tend to cause the bulbs to rot
Step 4. Place the pot in full sun
Allium bulbs can grow in partial sun and light shade, but they thrive in areas with full sun. Place the pot in a location that receives at least six hours of direct sunlight each day.
- Large amounts of sunlight will help the allium develop strong stems, so they can better support large blooms.
- If the container is too large to move, make sure it is placed where you want it before adding soil and planting the bulbs.
- If you are able to move the pot, place it in different areas of the house or garden during the day so that it receives as much sunlight as possible.
Step 5. Plant the bulbs with the tip upwards
The roots sprout from the rounded end of the bulb and the stem from the pointed end, so you need to make sure that the sharp end of the bulb is facing up when you place it in the soil.
- If you plant more than one bulb in each pot, make sure they are 6 inches apart and 6 inches away from the sides of the container.
- Dig a hole that is two to three times the diameter of the bulb when you plant it. Consider adding some compost (5cm) before placing the bulb in the hole to improve drainage and nutrition.
Step 6. Compact the soil on top
Compact the soil with your hands as much as possible to minimize the amount of air pockets. The bulbs will develop better if protected by pressed earth.
Step 7. Water thoroughly
Water the bulb until you see a little water flowing from the drainage holes at the bottom of the container. The soil must be saturated and heavy for it to be pressed around the bulb.
Method 3 of 3: Part Three: Caring for Alliums
Step 1. Water during the active growth phase
Allium bulbs need very little moisture, but you should be giving about 2.5cm of water per week. You don't have to water them during regular periods of rain, but it is advisable to water lightly during dry periods.
You just need to water the bulbs during their active growing periods, in spring, summer and early fall. Once the plant enters dormancy, you can stop watering
Step 2. Leave them alone
You shouldn't worry about pests, rodents, or diseases when caring for alliums. They are not susceptible to any serious diseases and actually tend to chase away deer, rodents and most insects. As a result, neither pesticides nor fungicides are needed.
Because plants of the genus allium are so good at deterring garden pests, they are often used as plants suitable for edging. Consider placing the allium around the perimeter of your garden to protect the most tempting flowers
Step 3. Cut carefully
If you decide to pick the flowers for decorative purposes, leave out as many leaves as possible. The bulb produces flowers annually, but each season it needs to gather as many nutrients as possible through photosynthesis. Its leaves are fundamental in this process.
Allium flowers can be used in bouquets and similar decorations, just like any other flower in the garden. Some stems may have a light onion scent, but in most cases the scent is not perceptible to humans
Step 4. Wait for the dormancy stage before cutting the foliage
The leaves tend to turn yellow in mid-summer. Once you see them die naturally, you can bet the plant is entering dormancy. You can cut off the leaves and foliage at this point.
Don't trim the foliage after the blooms fall off. The leaves still need to gather sunlight to produce energy so that the bulb grows stronger for the next season
Step 5. Consider light feeding in the spring
While not strictly necessary, it can be a good idea to give the bulbs a light potassium-based diet during early spring before you see the stems sprouting through the soil.
- For medium and good soils, this is actually not necessary. Consider doing this however if the soil conditions are poor.
- Adding potassium will encourage root and bulb formation. This applies to any potassium-rich fertilizer.
Step 6. Split only when necessary
If you notice a decrease in flower production after a few years, it may be necessary to divide the bulbs and replant them to encourage better growth.
- This is especially true for the smaller bulbs. Many large bulbs are able to multiply themselves and take care of the process without your intervention.
- Divide the bulbs after they enter dormancy, but before the earth cools. Dig up the cluster of bulbs using a garden pitchfork, working carefully to avoid making cuts in the bulbs.
- After removing the cluster of bulbs, gently shake off the excess earth before carefully separating the bulbs by removing them one at a time. Make sure you untangle the roots and not tear them.
