Growing dahlias indoors can be a challenging task, especially during winter, when daylight is limited. However, this doesn’t mean you can’t enjoy the beauty of these flowering plants throughout the year. With the right equipment, preparation, and knowledge, you can easily plant dahlias indoors and enjoy their blooms during the colder months. In this post, we’ll answer the question-Can you Grow Dahlias Indoors year round?And guide you through the process of planting dahlias indoors and offer tips to help your plants thrive all year.
Best Dahlias to Grow Indoors
Not all varieties of dahlias fare well indoors, and your choice of variety can heavily influence your success. For indoor cultivation, dwarf or smaller dahlias are often the go-to choices due to their manageable size and fewer light requirements. Varieties such as the ‘Gallery Art Deco’ with its vibrant, orange-red bloom, or the ‘Gallery Van Gogh’ with its yellow petals and deep orange center, are excellent choices. Both these varieties grow up to 18-20 inches tall and are ideal for indoor containers. Another great option is the ‘Twyning’s After Eight’ variety, noted for its white flowers contrasting a dark, almost-black foliage. This plant can grow up to 30 inches tall, which is still manageable for indoor growing. Remember, the key is to choose varieties that suit your indoor growing conditions and personal preferences.
Choose the Right Containers
Selecting the right containers is a crucial aspect of growing dahlias indoors. Dahlias require ample room to grow, so a broad and deep pot is often the best choice. For smaller dahlias like ‘Gallery Art Deco’ or ‘Gallery Van Gogh’, a pot that is at least 12 inches in diameter and depth will suffice. Larger varieties like ‘Twyning’s After Eight’ may require a pot up to 18 inches in diameter. The material of the pot also matters. Opt for terracotta or ceramic pots as they are breathable, allowing excess moisture to evaporate, thus preventing water-logging and keeping the roots healthy. Ensure your chosen pot has good drainage holes at the bottom to allow excess water to escape. Remember, the right pot can make a significant difference in the successful growth of your indoor dahlias.
Preparing the Soil
When it comes to preparing the soil for your dahlias, drainage and fertility are two key factors to consider. Dahlias prefer well-drained, loamy or sandy soil that is rich in organic matter. Start with a high-quality potting mix and amend it with compost or well-rotted manure to improve fertility. You can also add a small amount of perlite or sand to enhance drainage and prevent water-logging.
It’s essential to maintain a slightly acidic to neutral pH level (6.0 to 7.0) as dahlias do not fare well in overly acidic or alkaline conditions. You can conduct a simple soil test using a home kit to determine the pH level. If the soil is too acidic, add garden lime to bring up the pH. Conversely, if the soil is too alkaline, you can add sulfur to lower the pH. You can use this soil meter to test nutrient and pH levels.
Once your soil mix is prepared, fill the pot, leaving about 2 inches from the top to allow for watering. Remember, good soil preparation is the foundation of successful dahlia growth and blooming.
Planting Your Dahlias
The process of planting your dahlias begins with placing the tubers in the pot. Lay the tuber horizontally around 2 to 4 inches deep with the eye (the point from where the stem will grow) facing upwards. Ensure that the eye is at least 1 to 2 inches below the soil surface. If you are planting multiple tubers in the same pot, maintain a distance of about 2 feet between the tubers to provide enough room for growth.
After positioning the tubers, gently cover them with soil. Water the soil thoroughly but be careful not to overwater, as this can lead to tuber rot. The soil should be moist, not waterlogged.
Place the pot in a location that receives at least 6 to 8 hours of direct sunlight every day. While dahlias can tolerate partial shade, they truly thrive in full sun. If you live in an area with limited sunlight during winter, consider using grow lights to supplement natural light.
Once planted, it may take between 14 to 20 days for the dahlia shoots to appear above the soil. During this period, keep the soil consistently moist and watch out for any signs of disease or pests. With the right care, your indoor dahlias will soon start to grow and, eventually, bloom into beautiful flowers.
Light and Water Requirements
Dahlias thrive when they receive ample sunlight and appropriate water quantities. As mentioned earlier, dahlias require at least 6 to 8 hours of direct sunlight daily. This requirement is especially crucial for indoor dahlias, as they might not get as much natural light as their outdoor counterparts. If your indoor setup doesn’t naturally provide this much light, consider augmenting with grow lights. These can help ensure your dahlias get the light they need to grow and bloom.
In terms of watering, dahlias prefer a consistent watering schedule that keeps their soil moist but not waterlogged. A good rule of thumb is to water deeply once the top inch of soil feels dry to the touch. However, keep in mind that overwatering can lead to problems such as root rot, so it’s always better to err on the side of caution. Dahlias also prefer their water at room temperature, so avoid using very cold or hot water.
Monitoring your dahlias’ light and water needs will contribute significantly to their ability to grow and bloom indoors. Regularly check on your plants to ensure they are receiving the right amounts of both, and adjust your care routine as needed. This attention to detail can be the difference between a thriving dahlia plant and one that struggles to survive.
Fertilizer Needs
Dahlias, being heavy feeders, require regular feeding to bloom well. A well-balanced fertilizer that provides a good dosage of the three main macronutrients – Nitrogen (N), Phosphorus (P), and Potassium (K) is essential. An NPK ratio of 5-10-10 is often ideal, as it encourages strong root development and abundant flowering, without causing excessive foliage growth at the expense of the blooms.
Start feeding your dahlias with the fertilizer once the sprouts are visible above the soil surface. Thereafter, continue feeding them every four weeks throughout their growing season. Always water thoroughly after applying fertilizer to facilitate nutrient absorption and prevent root burn.
Remember, while fertilizing is vital for your dahlias’ health and blooming, over-fertilizing can be detrimental. It can lead to lush, soft growth that’s more susceptible to pests and diseases. Always follow the recommended dosage instructions on the fertilizer label and adjust as necessary, depending on your dahlias’ overall health and growth response.
Deadheading for New Blooms
Deadheading, or the process of removing spent flowers from your dahlias, is a crucial part of their care routine that can encourage a more abundant and prolonged blooming period. Once a flower fades and begins to wilt, use a pair of clean, sharp pruning shears to cut the stem back to the next set of leaves. This practice not only helps to keep your dahlias looking fresh and tidy, but it also stimulates the plant to produce more blooms in an attempt to ensure its propagation.
Remember to be gentle while deadheading to avoid damaging the stem or adjacent flowers. It is best to perform this task in the early morning or late evening, when temperatures are cooler, to minimize stress on the plant.
By carefully monitoring and regularly deadheading your dahlias, you can motivate them to produce a delightful display of flowers throughout their blooming season. Deadheading can be a truly rewarding part of indoor dahlia care, allowing you to actively engage with your plants and contribute directly to their vibrant displays of color.
Pest Control
Dahlias, like many plants, are susceptible to certain pests which can harm their health and impede their growth. The most common pests that plague dahlias are aphids, slugs, and thrips.
Aphids are small, soft-bodied insects that tend to gather on the under-surface of leaves or flower buds. They suck sap from the plant, leading to distorted growth and can also spread disease. Spraying your dahlias with a mild solution of soapy water can help control aphids. For heavy infestations, consider using a specific insecticidal soap or a low-toxicity insecticide.
Thrips are tiny, slender insects that feed on dahlias by puncturing their leaves and sucking out their contents, resulting in a stippled or silvery appearance. Insecticidal soaps can be effective against thrips, but it’s important to thoroughly cover all plant surfaces, as the insects can hide in hard-to-reach places.
Always remember, healthy plants are less likely to succumb to pest damage, so ensuring your dahlias are well-tended is the best way to prevent pest issues. Regularly check your plants for signs of pests and treat any infestations promptly to ensure your dahlias continue to grow and bloom beautifully.
Moving Dahlias to the Patio in Spring and Bringing Them Back Indoors
The best time to move your dahlias outdoors to the patio is in the late spring when all danger of frost has passed. Dahlias are very sensitive to cold, and exposure to freezing temperatures can damage or kill them. So, wait until the average overnight temperatures in your area are consistently above 50°F (10°C) before moving your plants outside.
While on the patio, ensure that your dahlias continue to receive at least 6 to 8 hours of sunlight each day and protect them from strong winds which could damage their stems. Also, maintain their watering and feeding schedule, and monitor them closely for any signs of pests or disease.
As fall approaches and temperatures start dropping, it’s time to consider moving your dahlias back indoors. Dahlias do not tolerate frost, so it’s critical to bring them in before the first frost of the season. Monitor the weather forecast closely and plan to transfer your dahlias indoors when the overnight temperatures begin to consistently drop below 50°F (10°C). Once back indoors, locate them in a sunny spot or supplement with grow lights, maintain their care routine, and continue to enjoy their blooms until they naturally die back and enter their winter dormancy period.
Soil Cleansing Before Moving Indoors
Before moving your dahlias indoors, it’s important to cleanse the soil of any potential pests or diseases. One effective method is to give the soil a soapy water bath. To do this, remove the plant from its pot and gently shake off as much soil as possible from the roots. Fill a large basin with lukewarm water and add a few drops of mild, unscented liquid soap. Submerge the root ball in the soapy water and gently swish it around to cleanse the roots and remaining soil. Finally, rinse the roots in clean, lukewarm water to remove any soap residue. This cleansing process can help ensure that your dahlias return indoors pest-free and ready for their winter dormancy period. Make sure to repot your dahlias in freshly cleaned pot with clean, fresh well-draining potting mix and return them to their well-lit indoor location.
Happy Gardening!
Growing dahlias indoors is an excellent way to keep your garden blooming all year round, even during winter when the weather is harsh. Now that you know how to plant dahlias indoors, you can avoid the hassle of waiting for the growing season to come back. Remember to choose the right type of dahlias, get your containers ready, provide enough light and warmth, fertilize and water properly, and monitor your dahlias consistently. With these tips, you’ll be able to enjoy the beauty of dahlias indoors all year long!
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