Planting flower bulbs: when, where & how deep?

With flower bulbs you can put your own little surprise in the garden. If they are buried deep in the ground, wonderful flowers appear in the same place months later.

When buying, make sure that the flower bulbs are firm and fresh. If possible, they should not be stored for long. However, it is important to wait until the correct time to plant the bulbs.

Tip: There are many plants that can survive winter with the help of underground renewal buds. Such plants are called geophytes. There are rhizome, tuber, and bulb geophytes, as well as those that form a root spawn. So not all plants that survive in the ground are bulbous plants. Crocus, dahlia, begonia, gladiolus and cyclamen, for example, form tubers, while irises push their leaves out of rhizomes.

Planting flower bulbs: when is the right time?

Although autumn is considered the time of year for planting bulbs, there are also species that are planted in spring or even summer. When to plant flower bulbs, among other things, depends on the flowering time and the frost tolerance of the plant species.

Plant bulbs in spring

Some plant species form bulbs, the flowers of which appear in summer. Such species are usually also sensitive to frost, which is why you should plant these flower bulbs in spring. You usually wait until no more severe frosts are to be expected, i.e. until the end of April or May. The summer-blooming geophytes include, for example:

• Dahlias (Dahlia)
• Gladioli (Gladiolus-Hybrid)
• Anemones (anemone), for example autumn anemones (Anemone hupehensis) or summer anemones (Anemone multifida)
• Star gladioli (Acidanthera bicolor)
• Tuberous begonias(Begonia tuberhybrida-Group)
• Indian flower tube (Canna indica-group)
• lily of the valley (Convalaria majalis), can be set both in spring and in autumn
• European cyclamen (Cyclamen purpurascens), to be planted in spring or summer
• Summer hyacinth (Galtonia candicans)
• Lilies (Lilium), for example the golden ribbon lily (Lilium auratum), the Madonna Lily (Lilium candidum) or the Turkish lily (Lilium martagon)

Lilies also bloom in summer, but due to their lower sensitivity to frost, they can be planted as early as March or in autumn. Lilium henryi is even preferred to be mated in autumn.

Plant bulbs in summer

Some geophytes do not bloom in spring or summer, but rather in autumn. Depending on their heyday, they are also set later. The correct time to plant bulbs or tubers is in August and September. The flowers appear just six weeks after planting. Well-known autumn bloomers are for example:

• Autumn crocus (Colchicum autumnale)
• Splendid autumn crocus (Crocus speciosus)
• European cyclamen (Cyclamen purpurascens), which can also be planted in spring

Plant bulbs in autumn

Most of the time, when you think of flower bulbs, the early bloomers immediately come to mind. The bulbs are planted in autumn and the flowers appear the following spring. Pay attention to the weather at the time of planting. If autumn is particularly mild, the plants can sprout too early. Depending on the type of plant, the bulbs are placed in the ground between September and November. Well-known early bloomers are for example:

• Crocuses (Crocus), like the spring crocus (Crocus vernus)
• Daffodils (Narcissus), like the yellow daffodil (Narcissus pseudonarcissus)
• snowdrop (Galanthus), like the Turkish snowdrop (Galanthus elwesii)
• Bluestars (Scilla), such as the two-leaved squill (Scilla bifolia)
• Tulips (Tulipa)
• leek (Allium), like star ball leek (Allium christophii), Golden leek (Allium moly) and
  Wild garlic (Alium ursinum)
• Anemone (anemone), like the wood anemone (Anemone nemorosa)
• Prairie lilies (Camassia), like Leichtlin's prairie lily (Camassia Leichtlinii)
• Ordinary snow pride (Chionodoxa luciliae)
• lily of the valley (Convallaria majalis)
• Spring cyclamen (Cyclamen coum)
• Winterling (Eranthis hyemalis)
• Steppe candles (Eremurus), like the narrow-leaved steppe candle (Eremurus stenophyllus)
• Chess flowers (Fritillaria), as the Checkerboard flower (Fritillaria meleagris)
• Dog's tooth lily (Erythronium dens-canis)
• Bunny bell (Hyacinthoides), like the common rabbit bell (Hyacinthoides non-scripta)
• Garden hyacinth (Hyacinthus orientalis)
• Single-flowered spring star (Ipheion uniflorum)
• Knot flowers (Leucojum), like the Märzenbecher (Leucojum vernum)
• Henry's lily (Lilium henryi)
• Lumpy grape hyacinth (Muscari comosum)
• Milky Stars (Ornithogalum), like the Great Milky Star (Ornithogalum sochi)

At a glance: When should you plant which flower bulbs?

• The exact time of planting depends on the flowering time and frost sensitivity of the plant species.
• Summer-blooming geophytes are usually planted in spring.
• Early bloomers are usually set in autumn.
• A few bulb plants are planted in summer.

The right location

The right location naturally depends on the type of plant. Most early bloomers, however, prefer a bright and sunny location. They already sprout before the trees have finished their leaves in order to take full advantage of the limited amount of light in spring. Exceptions are wild garlic, dog's tooth, hare bells, Turkish lily and cyclamen. These require a shady to partially shaded place. In addition, most garden varieties prefer nutrient-rich and water-permeable soil. The formation of waterlogging should be avoided at all costs so that the flower bulbs do not start to rot. For more information, see our specialty articles, which you can find above.

Plant baskets for flower bulbs

Because mice, especially Voles, like to grab the flower bulbs in the garden, plant baskets are often used to help. These special planting baskets for flower bulbs are buried in the ground with the bulbs and serve as a barrier for rodents digging underground. In addition, with the help of the plant basket, it is easier to get the bulbs out of the ground to overwinter or hibernate.

Flower bulbs in a pot

You can also plant bulbs in pots. The vessel should be deep enough and have a drainage hole. In addition, the creation of a drainage layer is recommended. A nutrient-rich and well-drained substrate, such as ours, should also be used in pots Plantura organic potting soil, be used. Our organic, peat-free soil remains structurally stable for a long time and is pre-fertilized with important nutrients for the plants. Due to the expanded clay it contains, it is permeable to water and does not tend to become waterlogged. After planting, the planter is also placed in a bright and sunny place in the garden or on the balcony.

tip: Planting tulip bulbs in pots is worthwhile: they have to be warm and dry during the summer, which can be easily achieved in a plant pot with a very permeable substrate.

Hibernate flower bulbs

To overwinter the flower bulbs in pots, frost protection should be installed or sheltered winter quarters should be found, as the soil in the pot can easily freeze through.
For frost-sensitive plants such as tuberous begonias, dahlias, gladioli and star gladioli, some ornamental onion species (Allium aflatunense, Allium giganteum), canna and crown anemones and summer hyacinths, effective protection against frost is essential, both in pots and when planted in the ground.

Flower bulbs in a glass

Bulbs can also serve as decorative heralds of spring in the warm room. Suitable bulbs are stored in cold stores as early as autumn in order to elicit an earlier flowering from them with this simulated winter. Alternatively, you can buy your own flower bulbs in autumn, store them in a cold place - for example in a shed, naturally well protected from mice - and bring them indoors in late winter or early spring. Now they are used for “forcing”: they are brought into the warmth and fooled into thinking that it is time to sprout. Driving hyacinths is just as possible as knight star (Hippeastrum) and tazettes (Narcissus tarzetta).

Driving flower bulbs in a glass - Instructions:

• Use prepared flower bulbs - they must have experienced a cold stimulus.
• Cover the glass with a net or use one with a waist.
• Fill the vessel with water - this should ideally be sterile by boiling it.
• Leave at least 1 cm space between the onion and the water.
• Put in the onion.
• Place in a bright and cool place at approx. 10 ° C and a cardboard cone to darken the onion until it is lifted by the shoot.
• Top up water regularly.
• When flower buds appear, the jar is placed in a warm place.
• Soon after, the flowers show up. Do not choose a location that is too warm or at least move to a cool room at night - this will keep the plant longer.
• After flowering, the bulb can be planted and cultivated further.

Instructions for planting flower bulbs

To plant bulbs, proceed as follows:

• Dig the planting hole: It should be deep enough that the tip of the onion is 1.5 times the height of the onion in the ground. This information is a rough "rule of thumb": You can usually find precise information on the packaging of the planting material. If a drainage or substrate layer is filled in, the hole must be dug correspondingly deeper.
• In heavy and impermeable garden soils, fill in a drainage layer of sand or gravel to avoid waterlogging.
• Filling in substrate: Use a high-quality substrate, such as our pre-fertilized, peat-free Plantura organic potting soil.
• Stick the onions firmly into the soil with the tip pointing upwards.
• Place the bulbs at a suitable distance, as recommended for the respective plant species.
• Plant onion plants in groups for good effects.
• Cover with soil, press down and water.

Can you still plant germinated bulbs? Yes, you can still plant bulbs that have already sprouted. Bulbs driven in spring should not be brought outside and planted in pots or soil until mid-May. They can now photosynthesize with their green foliage and thus collect energy for the budding of the following year. If, unfortunately, you have flower bulbs that have sprouted too early on hand in autumn, it is better not to plant them out: they are now too sensitive to frost and would freeze to death. Overwinter these onions planted in fresh soil in a cool and light place and also plant them outdoors in spring.

How do you plant bulbs around?

You put flower bulbs with the tip, i.e. with the rather elongated side up, in the ground. With some rather flat onions, it is not that easy to see which side is right. Sometimes you can already see a root attachment that should point downwards. This place is also called onion crust, onion slice or onion cake. Some plants also make it to the surface if stuck upside down in the soil. They then grow up around the bulb once and only need a little more time to break through the surface of the earth. However, it can also be that your energy is insufficient for the detour and the plant never reaches the surface - so position your flower bulbs as correctly as possible.

How deep should you plant bulbs?

How deep you should plant bulbs depends on the size of the bulb. As a rule of thumb for the depth, 1.5 times the height of the flower bulb is recommended. This means that as soon as the onion is in the ground, 1.5 times the onion height is poured back into the ground. So the hole has to be dug a little deeper at the beginning.

Lasagna planting with flower bulbs

In a lasagna planting with flower bulbs, also called tiered planting, different flower bulbs with staggered flowering times are stacked in a planter. Different bulb plants bloom over a longer period of time without having to replant. If you plant bulbs according to the lasagna principle, the plants that bloom first come to the top. Those that bloom last form the bottom layer. So you can - with enough space - achieve a continuous bloom over an entire vegetation period from February to September. Bulbs can of course also be planted in multiple layers in the bed.

Tulips are among the most famous bulb plants and enrich the garden with their flowers in spring. We show how to Summer tulips should so that they bloom again next year.