At this time of year it's all happening in the world of cut flower sowing & growing. In the last month I have planted out my autumn sown hardy annuals, started to harden off many of the plants I sowed in the winter ready to plant out after the risk of frost has passed, and I am continuing to sow and nurture the cut flower seeds from the February & March and April & May seed boxes. As you will see from the photographs below, the majority of my plants have had an amazing growth spurt in the last 5 weeks, vases full of cut flowers are just around the corner :)
As a reminder here's a summary of everything to consider over the coming months to care for your seeds and baby seedlings.
Hardy annuals As a general rule hardy annuals can be planted out now as the soil has warmed up. There's obviously regional variations and planting out is often later in colder northern gardens. Ideally your hardy annuals need to be roughly fist sized before planting out. As you will see from the information below I have now planted out all my autumn sown hardy annuals, but if you haven't got round to it yet, don't worry, it's not too late. For various reasons I didn't get mine into my patch until mid-May last year and I still got armfuls of flowers for months and months.
Half-hardy annuals should be planted out late spring or early summer, after all danger of frost has passed. I use this online tool to help predict the last frost date in our area
https://www.plantmaps.com/interactive-united-kingdom-last-frost-date-map.php
With the above in mind I've indicated below which plants are hardy and which are half hardy.
Ventilation
Seedlings are prone to a condition called damping off, it's a fungus that enters young seedlings from the soil. Good air circulation, to reduce humidity, along with not overwatering, is key to avoiding this condition. At this time of year I continually keep my greenhouse open, day and night
Watering
The most important requirement is, of course, water as small pots can dry out very quickly. However there's a fine balance as overwatering can cause damping off. I water most days but I try and keep my pots moist rather than damp.
Feeding
Around six weeks after sowing the seeds the nutrients in the compost may start to runout and the plant is looking unhealthy and starting to yellow. You might want to give them a liquid feed, something that is high in potash, like liquid tomato feed is ideal. Avoid high nitrogen feeds as they promote leggy growth which we want to try and avoid.
Pinching out
Pinching out benefits certain plants that have a tendency to shoot upwards and produce a leggy plant with only one stem. Pinching out encourages bushier growth, numerous stems and plenty of flowers. I have indicated below which plants will benefit from pinching out.
Potting on
If you're not ready to plant our your flowers into your patch and you turn your pots upside down and you can see the roots appearing through the drainage holes, it's time to transplant them into larger pots. Try and find pots that are one size larger, and carefully remove the plant by loosening the root ball so it comes out whole. Put it in the new pot on a base of fresh compost and fill around the sides with fresh compost too.
Second/successional sowing
As a number of flower seeds can be sown over the next few months, now is a good time to consider if you want to do a second or third sowing of any of the seeds we sowed last year or earlier this year, I've indicated alongside each plant, below, in which of the forthcoming month/s they can be sown.
Hardening off
A few weeks before planting out into your patch the plants ideally need to be acclimatised to being outside, the process is called hardening off. This is done by putting plants outside during the day and then putting them back undercover at night for a week or so. Then leave them out overnight. If cold weather is forecast you might want to consider covering your plants with horticultural fleece. Half-hardy annuals are most vulnerable, I tend to find that the hardy annuals need less attention and even in the first week can be left out overnight if the weather is fairly mild.
Preparing your patch
If your patch is going in a raised bed, fill it with a mix of compost and topsoil. If your patch is going directly into soil then weed the area well and fork it over adding some compost to improve the nutritional content.
Planting plans
A little bit of planning goes a long way when it comes to working out what to plant where in your cut flower patch. Put the taller plants at the back (north end) and smaller ones at the front, also allow the right amount of space for each plant, I think it's a common mistake to plant your flowers too close together and as soon as they mature your patch becomes overcrowded and difficult to mange. We've devised what I hope is a relatively simple Cut Flower Patch planning tool, you can find it here.
Support
Providing some form of support for your cut flower patch is important as it will need protecting from the wind and rain. However even if your patch is in a sheltered spot many of the flowers will grow very tall and the stems snap easily.
Probably the most popular and effective method for cut flowers is to stretch jute netting over your patch at around 45cm high, you might find this Sarah Raven video useful if this is something you are considering for your patch.
As my cut flower patch is in the front garden I want something that is more pleasing to the eye so I simply use canes and a plastic gardening ties which seems to do the trick. Sweet peas need more of a structure using either a wigwam or tepee of bamboo, hazel or willow secured tightly with twine.
The information below is grouped by the month the seeds were included in our Cut Flower Patch seed boxes. For the purposes of comparison, for each plant I specify the number of weeks since sowing as I am aware that not everyone is sowing their seeds at exactly the same time. The photographs were taken on the day of writing this blog.
The August Seed Box - Corncockle, Cornflower, Iceland Poppy, Nigella, Larkspur
Corncockle - Week 38
Classification: hardy annual
To feed or not to feed: not necessary
Pinch out: no
Over the next month: Corncockle is my first plant this growing season to flower. I suspect within the next few weeks some of them will be ready for cutting. Corncockle will need some sort of support, as you can see I've used a bamboo cane and a plastic gardening tie.
Second sowing/successional sowing: If you still have some corncockle seeds left you can direct sow them right up until the end of May.
Cornflower - Week 38
Classification: hardy annual
To feed or not to feed: not necessary
Pinch out: yes when about 15cm tall
Over the next month: I pinched out my cornflowers a few weeks ago and they have really benefitted. They have more than doubled in size in the last 5 weeks and are now quite bushy. There's the first sign of buds so, like the corncockle, I hope to be harvesting some cornflower over the forthcoming weeks.
Second sowing/successional sowing: Cornflower can be direct sown up until the end of May.
Iceland Poppy - Week 38
Classification: hardy annual
To feed or not to feed: not necessary
Pinch out: no
Over the next month: After hardening off for a couple of weeks I planted out my poppies into my patch, they are doing well and have started to show their first buds. Poppies are one of my favourites so am very much looking forward to the first flowers.
Second sowing/successional sowing: If you have any spare poppy seeds they can be direct sown up until the end of May.
Nigella - Week 33
Classification: hardy annual
To feed or not to feed: do not feed
Pinch out: no
Over the next month: Last year my nigella was a real winner but this year it seems to have struggled. I've planted out a few in the allotment and am hoping they are going to perk up a bit. I hope you are all having more success than me.
Second sowing/successional sowing: Nigella can be direct sown up until the end of May.
Larkspur - Week 30
Classification: hardy annual
To feed or not to feed: not necessary
Pinch out: yes, pinch out the growing tips when around 10cm tall
Over the next month: Last month I potted on my larkspur into larger pots as they weren't looking very robust, this seemed to do the trick and they are now out in my patch and are coming along nicely. Will keep them watered.
Second sowing/successional sowing: It's too late now to sow any larkspur for this season but if you have any seeds left you can so them August to November ready for harvesting next season.
The September Seed Box - Scabiosa, Snapdragon, Ammi Majus, Calendula, Orlaya
Scabiosa - Week 33
Classification: hardy annual
To feed or not to feed: not necessary
Pinch out: no
Over the next month: The scabiosa have now been hardened off and planted out in my patch. Compared to other plants they don't appear to have made much growing progress in the last 5 weeks. Hoping the forecasted warm and sunny weather might help buck them up a little.
Second sowing/successional sowing: Scabiosa can be sown indoors up until the end of May..
Snapdragon (Rocket Mixed)- Week 33
Classification: half-hardy annual
To feed or not to feed: not necessary
Pinch out: yes, pinch out the growing tips when they have four sets of true leaves
Over the next month: The snapdragon started to get a little pot bound so I potted them on into larger pots, and they have certainly benefitted. I pinched them out and am now hardening them off in preparation for planting out. Snapdragon are half hardy so I will need to wait until after the last frost to plant out.
https://www.plantmaps.com/interactive-united-kingdom-last-frost-date-map.php
Second sowing/successional sowing: It's a little late to sow snapdragon for this season but if you have any spare seeds you can sow them in September ready for next year.
Ammi Majus - Week 33
Classification: hardy annual
To feed or not to feed: not necessary
Pinch out: no
Over the next month: The ammi is in my patch and doing well and other than watering they can be left to grow.
Second sowing/successional sowing: Ammi can be direct sown up and until the end of June.
Calendula - Week 33
Classification: hardy annual
To feed or not to feed: not necessary
Pinch out: yes, when they reach around 10cm tall
Over the next month: The calendula have been pinched out, hardened off and planted out, and they're looking very healthy. Again they just need to be kept moist.
Second sowing/successional sowing: Calendula can be direct sown up until the end of May,
Orlaya - Week 33
Classification: hardy annual
To feed or not to feed: not necessary
Pinch out: yes, pinch out the growing tips when they have four sets of true leaves
Over the next month: Another hardy annual which I've pinched out, hardened off and is now in my patch. Just needs to be kept watered now.
Second sowing/successional sowing: Orlaya can be started indoors up until the end of May.
The October Seed Box - Sweet Pea Tango, Sweet Pea Mammoth, Achillea, Lavatera, Cerinthe
Sweet Pea, Tango - Week 29
Classification: hardy annual
To feed or not to feed: yes sweet peas are hungry plants.
Pinch out: yes, pinch out the growing tips when they have four sets of true leaves
Over the next month: I made a simple tent shaped structure for my sweet peas using bamboo canes, secured at the top with twine. I've used gardening ties to attach the sweet peas to the structure. Over the next month I will continue to tie them to encourage them to attach themselves to the structure. From now on, every couple of weeks, I will feed my sweet peas with a tomato feed.
Second sowing/successional sowing: If you have any sweet pea seeds left you can sow them outdoors up until the end of May.
Sweet Pea, Mammoth - Week 26
Classification: hardy annual
To feed or not to feed: yes, with a liquid tomato feed
Pinch out: yes, pinch out the growing tips when they have four sets of true leaves
Over the next month: My mammoth sweet peas have not done as well as the tango variety. The week 21 photo is from a second sowing so they are a little behind. I've planted some out in the allotment. Again I will continue to tie these to the structure and feed them with a tomato feed every two weeks or so.
Second sowing/successional sowing: If you have any sweet pea seeds left you can sow them outdoors until the end of May.
Achillea - Week 29
Classification: hardy perennial
To feed or not to feed: not necessary
Pinch out: yes
Over the next month: Am very pleased with the achillea as last year my crop was definitely lacklustre but this year they are looking good. I think they benefitted from being potted on last month and are certainly thriving in the patch. Will just be watering them over the next month.
Second sowing/successional sowing: Achillea can be sown indoors up until the end of May.
Lavatera - Week 29
Classification: hardy annual
To feed or not to feed: feed with a liquid tomato feed once a month
Pinch out: yes
Over the next month: Another one that's looking happy in my patch . In the next month I'll feed with a liquid tomato feed. Lavatera is a good plant for borders too, therefore as I have some spares I am going to pop some into the beds in our back garden.
Second sowing/successional sowing: Lavatera can be direct sown outdoors up until the end of May.
Cerinthe - Week 29
Classification: hardy annual
To feed or not to feed: feed with a liquid tomato feed once a month
Pinch out: yes
Over the next month: Since panting out into my cut flower patch the cerinthe plants have grown rapidly, so much so that I've had to support them with a bamboo cane and secured with a plastic gardening tie. I'll feed these in the next month with a liquid tomato feed.
Second sowing/successional sowing: It is now too late to sow any further cerinthe seeds for this season.
The November Seed Box - Godetia, Florists' Dill, Wild Carrot, Aquilegia, Astrantia
Godetia - Week 25
Classification: hardy annual
To feed or not to feed: not necessary
Pinch out: yes, when around 10cm tall
Over the next month: my godetia plants have grown very quickly, I've now pinched them out and put them in my patch. Will keep them watered.
Second sowing/successional sowing: Godetia can be direct sown outdoors up until the end of May
Florist's Dill - Week 25
Classification: hardy annual
To feed or not to feed: not necessary
Pinch out: yes
Over the next month: The florist's dill is another one that's had a growth spurt but I've neglected it. The plants are straggly and the roots are coming though the bottom of the pot. I will now pinch them out, pot them on into larger pots and harden them off in a weeks time.
Second sowing/successional sowing: Florist's dill can be direct sown up until the end of July.
Wild Carrot - Week 25
Classification: hardy annual
To feed or not to feed: not necessary
Pinch out: no
Over the month: Another plant that's grown very quickly in the last month, like the florist's dill these are becoming root bound so I'll pot on into larger pots and harden them off ready to plant out into my patch next month.
Second sowing/successional sowing: It's now too late in the season to sow any further wild carrot.
Aquilegia - Week 25
Classification: hardy perennial
To feed or not to feed: not necessary
Pinch out: no
Over the next month: Will leave the aquilegia in the greenhouse for another month and keep them watered. I'll be looking to plant them out into my patch late May.
Second sowing/successional sowing: Aquilegia can be sown indoors up until the end of June.
Astrantia - Week 20
Classification: hardy perennial
To feed or not to feed: not necessary
Pinch out: no
Over the next month: My astrantia are making slow progress, will give them another month in the greenhouse and will take a view at the of May.
Second sowing/successional sowing: It's too late to sow any further astrantia this season but they can be sown into pots in late autumn and left outside over winter for spring germination.
The December Seed Box - Corn Marigold, Bergamot, Delphinium, Viola, Snapdragon (Appleblossom)
Corn Marigold - Week 14
Classification: hardy annual
To feed or not to feed: not necessary
Pinch out: yes
Over the next month: The corn marigold, after a slow start, have now come on. I'll harden these off for a week or so and plant them out.
Second sowing/successional sowing: Corn marigold can be direct sown up until the end of May.
Bergamot - Week 14
Classification: hardy perennial
To feed or not to feed: not necessary
Pinch out: yes
Over the next month: I've had limited success with germinating these but I have a few good ones and I've pricked them out, although still quite small. These will stay in the greenhouse for a while longer.
Second sowing/successional sowing: It's now too late to sow any further bergamot seeds for this season.
Delphinium - Week 9
Classification: hardy annual
To feed or not to feed: not necessary
Pinch out: yes
Over the next month: I had zero success with my first sowing of delphiniums but have now had some limited success with my second sowing.
Second sowing/successional sowing: March to April
Viola - Week 14
Classification: hardy perennial
To feed or not to feed: an occasional liquid feed
Pinch out: yes
Over the next month: Another one that's grown rapidly over the last few weeks. Will harden these off over the next week or so and then plant them out into my patch.
Second sowing/successional sowing: Viola can be sown indoors up until the end of May.
Snapdragon (Appleblossom) - Week 14
Classification: half-hardy annual
To feed or not to feed: not necessary
Pinch out: yes, pinch out the growing tips when they have four sets of true leaves
Over the next month: Although these have grown rapidly, because snapdragon are half-hardy I'm going to leave them in the greenhouse for another 2 weeks before starting to harden them off.
Second sowing/successional sowing: It's now too late to sow any further snapdragon seeds for this season.
The February Seed Box - Zinna, Ageratum, Amaranthus
Zinnia - Week 6
Classification: half-hardy annual
To feed or not to feed: feed with a liquid tomato feed once flowering
Pinch out: yes, pinch out the growing tips when they have four sets of true leaves
Over the next month: This is my second sowing of zinnia, the first was the victim of a cold spell. Luckily the second sowing has done well. I've now pricked them out and will leave them in the greenhouse as they are still a little small to harden off. Please take care when pricking out your zinnia, they don't like root disturbance so handle with care, they're worth the extra time and effort.
Second sowing/successional sowing: Zinnia can be direct sown up until the end of May
Ageratum - Week 7
Classification: half-hardy annual
To feed or not to feed: feed with a liquid tomato feed
Pinch out: yes, pinch out the top 2.5cm when the plant has five true leaves
Over the next: Two sowings of ageratum and neither have survived. Hope you've had more success than me.
Second sowing/successional sowing: It's not too late to sow any further ageratum for this season.
Amaranthus - Week 6
Classification: hardy annual
To feed or not to feed: feed with a liquid tomato feed
Pinch out: yes
Over the next month: Again this is a second sowing. They are now looking good, I've thinned out the seedlings leaving more room for growth for the stronger ones. Will be pricking them out as soon as they get their first set of true leaves.
Second sowing/successional sowing: Amaranthus can be direct sown up until the end of May
The March Seed Box - Dahlia (Double Decrative Hybrid), Sunflower, Gypsophila
Dahlia (double decorative hybrid) week 6
Classification: half hardy annual
To feed or not to feed: yes, use a diluted tomato feed
Pinch out: yes
Over the next month: Look at these, in just 6 week they've germinated and have their first set of true leaves. Slugs love dahlias so they'll be staying in the greenhouse for a while longer so I can keep a close eye on them.
Second sowing/successional sowing: It's now too late to sow any further dahlia seeds for this season.
Sunflower week 6
Classification: hardy annual
To feed or not to feed: yes, use a diluted tomato feed
Pinch out: yes, when around 20cm tall
Over the next month: like the dahlias these have grown very quickly. Another plant loved by slugs so they'll be staying in the greenhouse for a while longer.
Second sowing/successional sowing: It's now too late to sow any further sunflowers for this season.
Gypsophila week 6
Classification: hardy annual
To feed or not to feed: yes, use a diluted tomato feed
Pinch out: yes
Over the next month: Another one that was ready to be pricked out within week of sowing. They need to be around fist size before planting out so will leave them in the greenhouse for a while longer.
Second sowing/successional sowing: Gypsophila can be direct sown up until the end of June
The April Seed Box - Dahlia (Bishop's Children), Rudbeckia, Cosmos (Purity)
Dahlia (Bishop's Children) week 3.5
Classification: half hardy annual
To feed or not to feed: yes, use a diluted tomato feed
Pinch out: yes
Over the next month: Only 3.5 weeks since sowing and they've germinated and have their first set of true leaves. Slugs love dahlias so they'll be staying in the greenhouse for a while longer so I can keep a close eye on them.
Second sowing/successional sowing: It's now too late to sow any further dahlia seeds for this season.
Cosmos (Purity) week 3.5
Classification: half hardy annual
To feed or not to feed: Feed cosmos in pots with a liquid fertiliser every couple of weeks throughout the summer. There’s no need to feed cosmos growing in your cut flower patch.
Pinch out: yes
Over the next month: Only 3.5 weeks since sowing and the cosmos has also germinated and have their first set of true leaves. Slugs love cosmos too so they'll be staying in the greenhouse for a while longer so I can keep a close eye on them.
Second sowing/successional sowing: Cosmos can be direct sown up until the end of June.
Rudbeckia week 3.5
Classification: half hardy annual
To feed or not to feed: If your garden soil is light and sandy, feed your Rudbeckia plants in spring when they start to come into growth with a general-purpose fertiliser.
Pinch out: no
Over the next month: Rudbeckia can be a little tricky to germinate but half a dozen or so have come through for me. Will keep them moist over the next few weeks and am hoping they come good. They're definitely worth the effort!
Second sowing/successional sowing: Rudbeckia can be direct sown up until the end of June.
That covers everything for this month. I'll be sowing our May seeds this week so will be posting the sow-along video soon.