Last updated on March 29th, 2022
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Wallflowers are a fairly easy plant to grow from seed and doing so can be particularly rewarding, with plants reaching heights up to 70cm and flowering through spring, summer, and sometimes even autumn.
Sowing wallflower seeds
With wallflowers, you can sow your seeds directly into the ground or you can choose to grow them in a seed tray indoors, before transplanting them further down the line.
Top-selling wallflower seeds
- Sow from last frost until August at ¼ inch depth. Germination temperature 20°C (68°F). Germination should take place within 3 weeks. If sowing in trays, prick out into small pots / trays until time to transplant or sow thinly direct into a nursery bed and thin out when large enough to handle to encourage strong plants.
- Keep weed free and moist during hot periods. (Note Wallflowers are susceptible to Club root in acid soils).
- In autumn plants should be moved to their final flowering position for the following spring. Space plants approx 12 inches apart and pinch out growing tips to encourage bushy growth.
- Plants should be removed at the end of spring once flowering has finished and replaced by annuals for succession of color. The plant may survive to the following year if pruned back heavily, but will look unsightly at first.
- Professional DEFRA licenced Quality Seed Supply only - Minimal packaging - Ziplock labelled bags - Instructions not attached - See details provided above for cultivation advice.
- A hardy biennial, flowers the year after sowing
- Cheerfully coloured blooms
- Richly fragrant flowers
- Great in spring beds, borders and large containers
- 40 cm growing height
- Pack of approx 100 seeds
- An unusual form of Wallflower with lilac flowers in May and June
- Plants grow to a height of about 30cm and are good for borders, gravel gardens and containers
- A hardy evergreen short-lived perennial that will self seed
- Sow indoors in winter/early spring for same year flowering, and summer/autumn for next year flowers, either indoors or directly into cultivated ground
- A hardy biennial, flowers the year after sowing
- Perfect with dwarf tulips in spring beds
- Sweetly scented
- Compact dwarf plants, bright colours
- 30 cm growing height
When to sow wallflower seeds
If you sow them outside, you want to do it between May and June when the risk of frost damaging young shoots has passed.
Sow seeds in an area that get full sun
The area in which you plant should be a place with access to full sunlight, the more sun the better. There are a few varieties of wallflowers that will tolerate light shade if you have no other option, but it is recommended that you find an area with access to a lot of sun. Aside from the light requirements, wallflowers are quite flexible in that they will tolerate poor soil so you don’t have to go through a great deal of hassle to try and change your soil. The one caveat to this is perennial wallflower is that it requires neutral or alkaline soil.
Sow seeds in fertile but well-drained soil
When you get ready to sow your seeds, you want to use fertile soil mixed with organic matter to help add better drainage qualities. Wallflowers, much like other flowers, do not appreciate being waterlogged so it’s important that you helped improve the drainage in the soil if needed, as well as in the pots if you are going to grow them in containers. Good soil will prevent them from drying out too quickly but will also add good drainage so they don’t get waterlogged.
Add high potash feed to the soil
Before you put the seeds in the ground you should mix a high potash granular fertiliser into the soil. This will go a long way towards helping the new plants establish themselves once they have started growing.
Planting the wallflower seeds
When you come to planting from seeds, put the seeds directly in the ground no more than 13mm deep, in rows that are 30cm apart. Once the seeds are in place, cover them with fine soil and water them. As they start to grow be careful not to let the soil dry out.
Germinating wallflower seeds indoors
If you want to germinate from seed but you aren’t ready to put them directly in the ground where they will reside permanently, you can use things like seed trays or propagators. All of these are designed to help you grow the seeds indoors. If you choose to do this make sure the temperatures remain between 13°C and 15°C, which is where a heated propagator can be handy.
These will be pricked out into new pots so space them evenly and on the surface of the soil and scatter a thin layer of soil or vermiculite over the seeds. If you have a seed tray rather than a propagator with a lid, cover it with plastic.
If you are using a propagator, there is likely a plastic lid that affixes to the top to create a closed greenhouse with something on the top to regulate the airflow. If you are growing them in small cups or containers (which is another option) you can cover them with plastic bags or plastic cups and plant them a little deeper. No matter what you do the idea is the same, you want to create an enclosed greenhouse that you can open from time to time to allow good airflow and watering.
Pot up into larger pots until the risk of frost has passed
If you choose to grow the seeds indoors first, as they start to establish themselves, especially the root structure, you will need to move them to slightly larger pots on multiple occasions until the time you can put them outside when the risk of frost has passed. This is usually around the end of May at the earliest for most parts of the UK.
That being said, it’s best to move them outside between September and October, where they should also remain 30cm apart in spacing. Again, the caveat here is with perennials. Perennials can technically be moved outside at any time but it is recommended that you wait until spring to achieve the best results and expose them to the outdoors over a couple of weeks to harden them off.
Pests on wallflowers
Once outside, the flea beetle becomes a risk. This is a tiny, shiny beetle that is the size of a pinhead and hops around like a flea. It can be a huge problem for new seedlings, peppering the new leaves with holes. It won’t kill your new wallflowers but it will stunt their development severely.
One good tip for getting rid of them requires the help of a friend. One of you holds a strip of yellow flypaper (the very sticky kind) and walks alongside the plants while the other follows closely behind and ruffles all the leaves. The flea beetles will pop up off the leaves once you ruffle them and stick to the strip. If they’re planted in the garden it can be easier to spray with a pesticide at the first signs.
Aftercare
Once you plant the wallflowers outside, you can add a layer of mulch to help with moisture retention and reduce weeds. Remember too that wallflowers need some support unless you are okay with them lurching from one side to another when it starts to get windy or rainy. As you first put them out you can help them to grow straight by giving them some sort of trellis or support structure.
Last update on 2024-11-23 / Affiliate links / Images from Amazon Product Advertising API
