Dahlias are fascinating flowers that can be found in various colors, and shapes and their flowers are big and striking. Originally from Mexico and Central America, dahlias are adored by gardeners worldwide because of their flowers that bloom from mid-summer till autumn. But they must be planted at the correct time depending on their type to be healthy and produce the best show.
In this article, we will go through the process of determining when to plant dahlias and other tips you need to know to make your flowers spectacular in your garden.
Understanding Dahlias: A Brief Overview
It is imperative to grasp the fundamental characteristics of dahlias before going deeper into the perspectives of planting. Tuberous perennials are herbaceous plants that arise from fleshy underground organs called tubers. They may be small bedding plants as well as large plants growing to 6 feet tall. The flowers they produce range from small pom pom-shaped flowers to flowers that can be as big as a dinner plate.
The number of officially recorded varieties is over forty, but there are thousands of cultivars, and each can have a distinctly different shape, color, and size of flowers. These plants are fond of friable, nutrient-rich, well-drained soil and sunny locations, which is crucial in terms of planting time. They should be planted at the proper time to have tubers develop good roots and avoid bloating or proliferation of the blooms affecting garden productivity.
When to Plant Dahlias: A Seasonal Guide
1. Consider Your Climate Zone
Planting dahlias mainly depends on this climate and the time to plant depends on the external weather conditions. Dahlia is sensitive to frost, which means that planting it in cold soil can result in rotting, poor development, or even death of the tubers. Expert’s advice for growing dahlias is that it is always best to plant them after the last frost and when the soil temperature is at least 60ºF to 70ºF (15ºC to 21ºC).
Cooler Climates (USDA Zones 3-6):
If there is a possibility of late spring frost in your area, plant dahlias directly in the garden only when the growing season is late May or early June. If you want an even earlier planting, you may pre-sprout the tubers in a container indoors 4-6 weeks before the last frost, then transplant them to the garden when there is no more risk of cold.
Mild Climates (USDA Zones 7-9):
In these zones, it is possible to start growing dahlias as early as late April or early May, when the ground is warm enough. Dahlias love the soft climate of their native environment provided they get the requisite amount of sunshine and water.
Warmer Climates (USDA Zones 10 and above):
Dahlias can be planted in March or April in warmer climates where winter frosts do not pose a threat to the plants. But you will need to provide some shade during the hottest part of the day so that the plants do not overheat.
2. Timing for Indoor Start
Another commonly used technique of growing dahlia is planting the tubers indoors to extend the season a little bit earlier than in areas with a short summer season. It is possible to put the tubers into pots so they can be grown in a warm and sunny area indoors, 4-6 weeks before the last frost in any given region.
Here’s how to start dahlias indoors:
- It is recommended that a tuber be planted in a container that is not less than 12 inches wide and deep to accommodate the growth.
- Find a good quality soil that drains very well and put it in the pot taking care to leave a little space at the top.
- Bury the tuber with the ‘eye’, that is, the growing point upwards to a depth of about 10cm.
- The humidity should be moderate and not let the soil become overly wet; the pot should be placed in a warm, sunny, area under 65-70F.
- After the frost is gone and the weather becomes warm transplant the dahlias into your garden; make sure the plant has enough room to grow.
Preparing the Soil for Planting
Having established a suitable time to plant dahlias in your locality, preparing good soil for the plants is the next big step. Dahlias prefer well-drained soil, which is soil rich in nutrients. Having the garden bed prepared is an added advantage, and the plants you are to grow need this kind of base to grow.
1. Soil Type and Preparation:
Dahlias are well suited to a well-drained, loamy soil. It is less suitable in marshy soil as this can easily result in root rot. If you have heavy clay soil should be improved by the use of compost, sand, or soils that have high organic material.
Test Soil pH:
Dahlias are best grown in a slightly acidic to neutral soil pH range, with an optimal of 6. 5, and 7. It is almost neutral and has 0 pH. The pH of the soil can be checked and regulated based on the main soil test kits and it can be augmented by the use of lime or sulfur.
Add Organic Matter:
Before planting, dig in compost or well-rotted manure. This increases the physical properties of the soil and enhances the nutrient content and root growth.
2. Spacing and Depth:
Space the dahlia tubers 45-60 cm apart to accommodate the size of the variety of the flower that you intend to grow. Some of them require more space because they are larger than others while the others can be planted at closer intervals because of their dwarf nature. Each tuber should be planted 10-15 cm deep with the “eye” facing up. Bury the tuber only slightly and do not water immediately after planting, if the soil is cold or wet. Planting in wet conditions leads to the rotting of tubers before they emerge on the ground surface.
Caring for Dahlias After Planting
After planting your dahlias, the care you give them will determine the growth and flowering pattern of the plant all through the growing season.
1. Watering:
When dahlias are established the soil should always be moist but this should not be confused with over-watering the plants. Too much water may cause rot while lack of water may cause slow growth of the plant when the plants are well-rooted and actively growing, water them thoroughly once or twice per week, depending on the climate. If the climate is very hot or dry, you will have to water at regular intervals to maintain adequate moisture.
One should water at the base of the plants to avoid wetting the leaves as this is a good breeding ground for diseases such as powdery mildew.
2. Fertilizing:
Dahlia plants are known to require many nutrients and it is recommended that they be fed all through the growing period. The fertilizer for the sansevieria is a balanced slow-release fertilizer with an N-P-K ratio of about 10-10-10 or 5-10-10, applied every month. Do not use fertilizers containing high levels of nitrogen as this will lead to a condition referred to as ‘legginess’ whereby the plant develops a lot of foliage at the expense of flowers.
3. Staking:
Some of the dahlia varieties are fairly large and the stems can be quite fragile requiring staking to avoid bending or breaking during wind or rain. It is advisable to place stakes or supports at the time of planting, to spare the roots later. They should be tied to the stakes as they grow to maintain a proper growth orientation.
4. Deadheading:
Deadheading of dead flowers is also important in the process as it pushes the dahlias to produce more flowers in the course of the season. It can be done by cutting off the flowers that have wilted and have no petals left, cutting right down to the nearest set of leaves. This not only neatens the plant but also helps it to focus on creating more flowers.
Harvesting and Enjoying Dahlias
Dahlias are usually cultivated for the ornamental purpose of the flowers and are particularly suitable for cut flowers and if these are cut and arranged properly they can last up to a week in a vase. Here are some tips for harvesting dahlias:
- Harvest cut flowers in the early morning or late evening when the heat is low, and the plants are relaxed.
- To prevent wilting or rotting of flowers, use sharp-pointed scissors or shears to cut the stems and put them in a container of warm water.
- Remove the lower leaves from the lower part of the stem so as not to rot in water.
- For maximum longevity, replace the water every day and avoid direct sunlight for the flowers.
Overwintering Dahlias: Preparing for the Next Season
Indeed, in regions where winter is harsh, it would be damaging to the dahlia for the tubers to remain in the ground. As soon as the top bits are frost-killed, it is time to dig up the tubers and keep them for the winter.
1. Digging Up Tubers:
It is best to loosen the tubers using a garden fork, beginning 6 inches from the stem to prevent damaging the tuber clumps. Leaving the tubers in the soil, loosen the soil around them carefully for the tubers to be free, and then gently knock off the soil.
2. Drying Tubers:
It is recommended to let the tubers dry for a few days in a cool and very ventilated region. After that, remove the dirt by shaking it off, and then cutting the stem of the plant back.
3. Storing Tubers:
Tubers should be kept at low temperatures in the dark and slightly moist in peat moss, sawdust, or vermiculite. Inspect them occasionally throughout the winter and if they are rotted, or shriveled, empty the containers.
Dahlias can be left in the ground in warmer climates they need to be protected by a thick layer of mulch in case of frost.
Conclusion
Dahlias are great, beautiful flowers that are good to know and have in your garden during summer and until the end of the fall season. Time is also important in planting dahlias since they can be easily killed by frost hence wait for the soil to warm up before planting. Dahlias will pay dividends in successive seasons provided the propagation, growth, and management of water, nutrients, and winter protection is correct.
