When Should I Plant Summer Bulbs?

To answer the question of When should I plant summer bulbs? lets first look at what bulbs are included in this group.

When should I plant summer bulbs? What Summer Bulbs Are Available?
There is a wide range of bulbs which fall into the category of ‘summer bulbs’ including agapanthus, alliums, begonias, cannas, crocosmia, dahlias, eucomis, freesias, gladioli, iris, lilies, nerines, peonies, etc. You will find these bulbs appearing in garden centres from spring or you can shop online where you are likely to find an even wider selection of bulbs, from the popular ones we have mentioned through to the more unusual summer bulbs.

Summer Bulbs - Agapanthus Agapanthus - also referred to as African Lilies - are an impressive, sun-loving bulb whose flower appears atop a tall, narrow stem. Usually in a range of wonderful blues, you will also find white and black agapanthus too. These bulbs don't mind having their roots restricted and will also tolerate dry conditions, making them ideal for narrow borders or containers. Plant outdoors in Spring once temperatures settle but if you want to give them a head start plant them in a container in your greenhouse and move outdoors when temperatures improve.

Summer Bulbs - Begonias We refer to begonias as being bulbs when technically they are a tuber. Tubers work in exactly the same way as a bulb but rather than a typically pointed shape with scaled surface, tubers look a little like shrivelled potatoes with at least one eye or green growing tip. Easy to grow, there are many varieties of begonia available ranging from those with an upright habit, to those with a trailing growth ideal for hanging baskets. They are also available in a glorious palette of colours from bright red through to coral, orange and yellow.

Summer Bulbs - Freesias Freesias can be planted indoors, grown in a pot or outdoors so can add colour to your home or garden. They can be planted in pots undercover between January through to March for early Summer flowering. Plant outdoors April through to June for late Summer flowering. Freesia bulbs are also referred to as corms - the difference between a bulb and a corm is that a bulb is made up of layers of nutrient-filled leaves whilst a corm is solid tissue without the layered scales that characterise a true bulb.

These summer bulbs will all provide a plethora of colour in your garden with minimum effort if you plant them at the right time and at the correct depth.

When should I plant summer bulbs? Plant In Spring But Watch The Weather
Summer bulbs need to be planted in Spring. In the UK Spring begins in March and ends in May, however we wouldn’t advise waking up on the first day of March and rushing into the garden to plant the summer bulbs you have bought and stored carefully away in a cool, dry space until Spring arrived. It may be the first of March, but you also need to take into consideration the temperature and condition of the soil.

Ideally you should be planting these bulbs once all chances of frost have passed, and the soil is beginning to warm up. Bulbs will start to grow when the soil temperature is a minimum of 13 degrees Celsius - if you want to check your soil temperature then a simple soil thermometer will show this for you.

What you also need to consider is the state of the soil – one of the main problems faced by bulbs is that the soil they are planted in is too wet and they rot – bulbs can cope with damp, well-draining soil but not by being surrounded by constantly wet soil. So, if it has been raining heavily then ideally wait a couple of days before attempting to plant summer bulbs – in fact if the soil is still soggy after a couple of days of dry weather, then it’s probably not the best place to plant your bulbs! If you want to improve the soil where you are to plant your bulbs, then spend a little time making sure it is loose and well drained. Use a hand trowel to loosen up the soil you are going to be planting in prior to placing your bulbs. If you have clay soil in your garden then to help with drainage it’s best to add in compost or leaf mould, manure or even composted bark to help break up the clay and improve the quality of your soil.

When should I plant summer bulbs? Planting Your Summer Bulbs Correctly
The final thing to consider when planting your bulbs is getting the planting depth right – if your bulbs aren’t planted deep enough then they are vulnerable to being eaten by pests visiting your garden, such as squirrels – whilst planting the bulbs too deeply could mean you will only see foliage rather than flowers if they manage to find their way to the surface of the soil.

The general rule of thumb when planting bulbs is that they should be planted two to three times their depth. There are a few exceptions to this rule – some bulbs must be planted at three times their depth such as gladioli or lilies, whilst others want to be planted just below the surface of the soil, such as dahlias and nerines. So ideally check the depth required before planting on either the bulb packet or with the supplier.

If you are new to bulb planting you should also remember that they should be planted with their pointed end facing upwards – or if the bulbs you are planting don’t have an obvious pointed end then look for where the roots come out and that is the end of the bulb that goes down. 

Our blog post When Should I Plant Summer Bulbs was created from our personal knowledge, information gathered by speaking to other gardeners or manufacturers in the gardening industry, by reading gardening magazines and devouring information from books and the internet. We aim to be as accurate as we can, so if you find a mistake, please remember, we’re only human. if you have any queries you can contact us today!