If you have cut back your lupins after they have flowered, you may be wondering when they will start to grow back. Their colorful, beautiful blooms make them a popular addition to any garden, and you may be eager to have them back in all their glory.
Lupins start to grow back in springtime after their season ends in winter. They sprout new leaves and stems in late March or early April, with flush blooms appearing in late May or early June. However, this varies depending on the weather and location.
In this detailed article, I will share with you everything you need to know about when lupins start to grow back, including how to care for them during this time. I will also give you tips on how to encourage new growth and ensure that your lupins have a long, healthy life.
Understanding Lupin Life Cycle
Understanding the lupin life cycle is vital for establishing when they will start to grow back. This will vary depending on the type of lupin you have, the climate, and weather conditions.
Lupins are herbaceous perennials that grow year after year. Each year, they will grow and bloom during their season before dying back down to the ground in winter. They will then start to sprout new growth in spring, ready to grow and bloom again the following year.
The lupins will sprout new leaves and stems during spring, usually from late March to early April. After a few weeks, the plant will start to produce flower buds, which will then bloom into flowers in late May or early June. Depending on the type of lupin, the flowers can be any color, from white and cream to pink, blue, and purple.
After the lupins have flowered, usually in winter, they will start to die back. The leaves will turn yellow and brown before falling off, and the stems will become woody. Eventually, the plant will be completely dormant until springtime, when it starts to grow again.
This is the general life cycle of lupins, but as mentioned, it can vary depending on the type of lupin and the climate.
For example, if you live in a region with a warm climate like Texas and Louisiana, the lupins may start to grow back earlier than usual. But if you live in a cooler region like Alaska, they may take longer to start growing again.
Most lupin varieties have a lifespan of 5-6 years, after which they will start to decline in vigor and may need to be replaced. However, some varieties can last for ten years or more with proper care. This includes annual pruning, fertilization, and mulching to protect the roots during winter.
Factors Affecting Lupin Growth
Several factors can affect when lupins start to grow back. This includes the lupin variety, climate, soil conditions, and the care they receive.
Lupin Variety
There are over 200 species of lupins, which can be divided into two main groups: annual and perennial. Annual lupins only live for one year, whereas perennial lupins will grow back year after year.
Most lupins grown in gardens are perennials, as they are more reliable and easier to care for. Annual lupins are often only grown as ornamental plants, as they can be challenging to get to flower a second time.
Different lupin varieties have different tolerance to cold weather and frost. This means that some varieties will start to grow back earlier than others.
For example, the Russell lupin (Lupinus polyphyllus ‘Russell’) is a pretty hardy variety that can withstand cool temperatures and even some frost. It is also one of the earliest blooming varieties, with flowers appearing in May.
Type of Climate
Lupins are native to temperate climates and prefer cool weather and lots of sunlight. They will not tolerate heat or humidity well and may start to wilt and die back if the temperatures get too high.
Additionally, high rainfall or moisture levels make them susceptible to fungal diseases, which can cause the leaves to turn yellow and brown. The sogginess can also cause root rot, which can kill the plant.
Soil Conditions
While lupins will grow in most soil types, they prefer well-drained soil rich in organic matter. They also prefer a slightly acidic to neutral pH level (6.0-7.5). If the soil is too heavy or has poor drainage, the lupins may start to wilt and die back.
Since the roots need oxygen to grow, they will not be able to get the nutrients they need if the soil is waterlogged. Poor drainage can also lead to fungal diseases, which can kill the plant.
The Care They Receive
Like all plants, lupins need to be adequately cared for to thrive. This includes watering, fertilizing, and weeding.
After cutting back the lupins in winter, regular watering is essential as it helps them start growing again in spring. You should water them deeply and regularly, especially during hot weather. The water will help to rehydrate the roots and encourage new growth.
A balanced fertilizer will also help replenish the nutrients in the soil and promote new growth. However, follow the instructions on the fertilizer packaging, as too much fertilizer can burn the roots.
Since weeds compete for the same resources as lupins (water, nutrients, and sunlight), keeping them under control is essential. Hand-pulling or hoeing around the plant’s base can help reduce weed growth. This will give the lupins a better chance to grow and thrive.
Tips on How To Encourage Lupin Growth
The splash of color that lupins add to the garden is undeniable. If you want to enjoy their beauty year after year, there are a few things you can do to encourage growth:
Choose the Right Variety
With over 200 species of lupins, choosing the right one for your garden is essential. Consider the climate, soil conditions, and tolerance to different weather conditions, including frost and heat.
If you live in a cold area, choose a variety that is known to be hardy. Russell lupins are an excellent option, as they can withstand cool temperatures and even frost.
Prepare the Soil
Lupins prefer well-drained soil that is rich in organic matter. If your soil is heavy or has poor drainage, consider amending it with compost or other organic matter. You can also add a layer of mulch to help retain moisture and suppress weeds.
If the soil pH is too high or low, you can adjust it by adding sulfur or lime. Lupins do well in slightly acidic to neutral soils (6.0-7.5).
Alternatively, you can grow your lupins in a raised garden bed or container. Raised garden beds offer well-drained, amended soil, and containers offer portability and drainage control.
Water Deeply
Water is vital for lupins to thrive. After cutting back the plant in winter, water it deeply and regularly during the growing season. This will help to rehydrate the roots and encourage new growth. However, avoid overwatering, as this can lead to root rot which can kill the plant.
Fertilize Regularly
While lupins have nitrogen-fixing bacteria on their roots, they need to be regularly fertilized. Phosphorus-based fertilizer will encourage healthy and robust root growth, essential for lupins to flourish.
You can use a slow-releasing fertilizer or apply compost around the base of the plant every few weeks. Ensure you follow the package instructions, as too much fertilizer can burn or damage the roots. After fertilizing, water your lupins deeply to help the nutrients reach the roots.
Control the Weeds
When left unchecked, weeds can take over the garden and crowd out lupins. Regular weeding is essential to prevent competition for the same resources, which can delay or stunt growth.
Hand-pulling is the ideal weed-control method as you can easily remove the entire weed, root and all. However, hoeing can also be effective if done regularly. You can also use herbicides, but they should be used as a last resort due to the potential harm they can cause to the environment.
Provide Mulch
Mulching is a great way to retain moisture, suppress weeds, and protect the roots from extreme temperatures. It also helps to give the garden a neat appearance. You can use organic mulches such as bark chips, straws, or leaves. These will eventually break down and improve the soil quality.
Inorganic mulches such as landscape fabric or black plastic can also be used but need to be replaced every few years. Apply a thick layer (3-4 inches or 7.6-10 cm) around the base of the plant, taking care not to pile it up against the stem.
Final Thoughts
Lupins start to sprout new growth in spring after the old growth has been cut back. To encourage healthy growth, water deeply and regularly, fertilize with phosphorus-based fertilizer, and control the weeds.
Mulching is also beneficial as it helps retain moisture, suppress weeds, and protect the roots from extreme temperatures. Ensure you also choose a variety suited to your climate and soil conditions.
With a bit of care and patience, you will soon have a beautiful lupin plant splashing a pop of color and life into your garden.
You may also like:
- Can Lupins Be Grown in Pots?
- How Tall Do Lupins Grow?
- What To Do With Lupins After Flowering – Everything you need to know
- When To Cut Back Lupins?
Hi! I’m Sophia, and I love plants – especially an expert in growing house plants. I stay in Chicago, United States of America, and through my blog and social media platforms, provide tips and tricks on how to grow healthy, vibrant plants indoors. Check out more here.