Raised Bed Gardening: May

gardening May

It’s May and the temperatures outside are starting to rise! For us it only means one thing – we are continuing with our raised bed gardening in an attempt to bring as many home-grown vegetables to our table as possible! In this article, we will tell you all the gardening jobs we do in May, as well as seeds we plant outdoors and plants we transfer from inside to continue growing outdoors!

If you’re just starting your gardening season, have a look at our guides for April and March. And if you are interested in building raised beds in your own garden, here’s a guide on how we did it from scratch!

May is one of our favourite months in the garden because we finish sowing and planting everything outdoors and move chillies and tomatoes to the conservatory (which for us acts as a greenhouse) permanently without being worried about it being too cold.

Gardening To-Do List for May:

  • Depending on the year and how much space in the raised beds I’ve allocated for various vegetables, May is when I plant further successions of salad leaves, rocket, carrots, spring onion etc. so that I can enjoy them for longer.
  • Sow all the herbs outdoors. I’ve sown the majority of them outdoors in April but now sow less hardy coriander and basil too.
  • Transfer tomatoes and chillies to their final pots and into the conservatory which acts as a greenhouse if you don’t have one.
  • Harden off any remaining plants that you’re planning to grow outside: courgettes and squash etc.
  • Now that soil is warm, keep an eye on any weeds appearing!
  • Thin out beetroot, spinach, carrots and any other plants that need thinning to give each plant enough space to grow.
  • If you have an issue with snails, slugs or aphids, take your preferred measures to get them under control now.
  • In summer, with less rainfall, you may need to water your raised beds a lot more often. If you’re currently using tap water, consider investing in a water butt to collect rainwater.
gardening May

What to Sow Indoors In May?

Anything and everything you haven’t yet sown. If you’re just starting off, you can sow the majority of the seeds indoors. Your harvest will come later, but your seeds should germinate quicker and seedlings grow quicker due to warmer temperatures and more sunlight. Sow Butternutnut Squash, Brussells Sprouts, Kale on your windowsill to move outdoors in July.

You may choose to sow your herbs in pots on your windowsill (which you can do all year round) or opt to sow directly outdoors in May. Tomatoes, peppers and chilli peppers can also be started indoors in May. But if you have a greenhouse, it may be worth sowing directly in the greenhouse.

What to Sow Outdoors In May?

Directly from Seed:

Courgettes: Courgettes may be my favourite vegetable to grow. They never failed us and they just keep giving from early August into October. Each plant gave us at least 6 courgettes over the season, and by the end of it, we are always scratching our heads thinking about what else to make with them. We planted half of the Ambassador Courgettes at the end of April and the rest we are planning in May to stagger the harvest.

Cucumber: This is our first year growing cucumber, so we are complete novices. Since we don’t have a greenhouse, we will try growing the Marketmore variety in two ways. 1. Sowing directly into the raised beds in a sunny spot at the end of May, covering the soil above the seeds with a cloche. 2. Sowing cucumber in small pots indoors and then planting out into raised beds when they are 10-15cm tall. We will update this post before sowing season next year to let you know how it went!

Herbs: If you haven’t sown your parsley, thyme, oregano earlier in the year, it is not too late to so the seeds outdoors in May. It is now time to sow your less hardy herbs that need more warmth too, including:

  • Coriander
  • Basil
  • Lemon Balm (Melissa Officinalis): many seem unfamiliar with this beautiful herb. I’ve grown up with it, using it to flavour lemonades, make tea, and even use in baking!

Carrots: If you haven’t sown early crop carrots, or looking to get further successive sowings in, main crop carrots can be sown at the start of May.

Spinach: Most of the spinach varieties are ok to sow outdoors in May. If you haven’t started growing yours yet, get them growing directly from seed outdoors in your raised beds. We sowed Trombone variety in rows in our raised beds at the beginning of May and expect to start harvesting in 6-7 weeks time. We grow a lot of spinach and cut the leaves often to promote further growth. Any excess, we freeze for autumn/winter months.

Salad Onions: we normally sow the second lot of spring onion (the first one was done in April) for a continuous crop later in the year.

Plant Out your Seedlings Outdoors:

Leeks: We first planted our Almera leeks in March in cell trays. Over the month of April, we have been taking the tray outside during the day to get the leeks acclimatised and ready to be transferred into the raised beds. Now that they’re about 20cm tall, we are planting them out. We trim the roots to 5cm and make 15 cm deep holes that are 15 cm apart. The tip I am going to use this year is to place the leeks in the holes gently, fill them with water but not infill them with soil. We are hoping to start harvesting them from October through to spring next year.

Brussels Sprouts: We started our Red Bull Brussels Sprouts in small pots in March. Now that they are about 15 cm tall, we are planting them in our raised beds. The important bit is to give each of them at least 50cm space all around. Other than that, Brussels need very little care. Simply make sure to water regularly during warm dry periods and expect to harvest from the end of October through to February/March.

Kale: we planted our Kale out in April, but if you started later, May might be a good month to plant them out. Harden the plants off by leaving them in trays/pots outside for periods of time. Then plant in your raised beds when they are about 15cm tall.

gardening May

What to Transfer to Conservatory If You Don’t Have a Greenhouse?

Pot Grown Tomatoes: Once the plants are large enough (approx. 20cm tall), they can be planted in their final pots (we use 30cm wide planers). Tomatoes like the warmth so you will ideally carry on growing them in a greenhouse, or, if you don’t have one, in a sunny conservatory.

In early May we will start taking the pots to the conservatory during the day and bringing them in at night. In the middle of May, we will start leaving them in the conservatory overnight. That is, of course very much weather dependent and may be done earlier if there is no risk of low temperatures. We still have 0-1C nights at the end of April, so we had to take it slow this year. Before you leave your tomatoes in the conservatory overnight, make sure the temperature doesn’t drop below 10-12 C at any point. We are continuing with weekly feeds with weak tomato feed, increasing the strength little by little as tomato plants grow.

As Cherry Tomato Plants grow, they will need support, so use sticks and strings to secure them. What is more, side shoots should be removed regularly before they get large, allowing easier picking off ripen fruits and reducing disease risk.

Chillies: Once your seedlings have 3-4 true leaves pot up into fresh compost. We use 9cm pots. At the end of May, when the plants are about 20cm tall, we transfer them into large pots/ containers (20-25cm wide) and mix in some slow-release fertiliser for best results. Move the plants into the conservatory when the temperature doesn’t drop below 12-14 C at night and make sure to water them regularly. Chilli plants will benefit from support – we use a small cane.


That is it! All of our sowing is pretty much done, just a couple of things to plant out in June! It’s now almost time to relax a bit and watch your vegetables grow!

Our other articles on what we do each month in Spring are below:

gardening May

Leave a Reply

Somebody Feed Seb