How to look after flowers in the heat

by Charlotte.Barnes on August 10, 2010

Although most flowers will thrive on hot, sunny days there are times when really dry spells can leave your plants looking a little tired.

Our guide will help you keep your plants at their healthiest during the summer…

Choosing your plants

Any flowers or plants native to hot climates will work well in your garden. But make sure you plant them either indoors to start with or after the last frost.

Try growing marigolds, lilies or sunflowers. All of these work well in direct sunlight.

If you are in a particularly dry climate, where it doesn’t rain very much, plants like aloe and various cacti won’t need watering – a small amount of rainfall will be enough. If you want to build a cacti garden, then you can put the plants in the ground, including the pot, then lift them out when winter comes and keep them inside until spring.

Mediterranean plants, such as lavender, have a great resistance to drought. Also, try filling flowerbeds with grasses and herbs as these are very tolerant to the heat.

Keep your greenhouse cool

Open doors and vents to let air circulate; this will help keep the greenhouse cool. Make sure that any compost doesn’t dry out.

Put up shade nets in early summer to protect plants from direct, scorching sunlight. Try to avoid watering plants in the middle of the day as this can scorch their leaves. Instead, try to water first thing in the morning or in the early evening.

If your plants prefer a humid climate, splash the floor with water in the morning – as it heats up it’ll evaporate into mist. Another option is to use a hand-held mister to spray your plants.

Cold water can shock the roots of the plants. Make sure you have a full watering can sitting in the greenhouse so you always have a supply of warmer water.

Bugs and diseases thrive in hot and humid conditions, so make a note of which of your plants are susceptible. Treat them with the appropriate fungicides and bug sprays. If you are unsure, then visit your local garden centre and explain the problem. More often than not they’ll be able to help you find the right treatment for your plants.


Using a good mulch – such as bark, leaf mould or well-rotted manure – can help to keep plants moist and give them a lot of useful nutrients. Mulching will keep the roots of your plants cool and will ensure they don’t dry out too quickly in the summer.

Make sure the soil is moist and weed-free before you begin, then spread a 5cm layer of your chosen mulch around the plants and finally smooth it out with a spade or trowel.

Bark comes in various grades – from ornamental bark to the finer types, which tend to rot down quickly. Well-rotted manure is available from stables and garden centres and is great for a fruit or vegetable garden.


This is essential to keep your plants looking healthy. If you normally water once a week, up this to twice or three times a week during really hot, dry periods. In the morning, give your plants a mist with warm water, especially those native to humid climates.

Tomato plant and garden toolsOutdoor pot plants will need to be watered everyday and if you find they are suffering in direct sunlight try moving them to a shadier area. Remember that smaller pots dry out quicker than big pots containing more compost.

Rainwater is much better for your plants than tap water. If you can collect rainwater, then use this to water your plants. Water during the evening as this gives the water time to soak down to the roots of your plants rather than evaporating straight away.

Test to see how far down the water is soaking by carefully digging up a small section of soil. You need to make sure the water is reaching deep down to the roots of your plants rather than just the top few layers of soil.

Sometimes it is just a matter of trial and error with your plants, but soon you will begin to know if they need a bit more water when it gets hotter just by how they look.

Cut flowers

Our expert florist Su Whale has given us some handy tips on how to keep cut flowers fresh, even in the summer heat:

  • Flowers have their own method of self-preservation – the cut end of the stem will seal over if it has been out of water for a length of time. This avoids any further loss of moisture but also stops fresh water being taken up. Because of this, the single most important thing you can do for your flowers is to re-cut the stems when you get them home.
  • Then, you need a clean vase, fresh water and ideally a sachet of flower food. Flowers are like people, they need food and water to survive!
  • Take off any leaves that will be under the water line. This is for two reasons – one, the leaves will rot which will in turn pollute the water and flowers need fresh water to survive (you wouldn’t want to drink it, neither do they!) Secondly, the leaves will be taking up valuable water and food that should be going to the flowers.

  • When you cut the flower stems, don’t ‘bash’ them. This is an old-fashioned thing to do which has no benefit to the flower at all. In fact, it has the opposite effect as, without getting too technical, the tiny tubes that take the water up the stem will have been damaged and so won’t work as efficiently.
  • In this warm weather, where you put your flowers is very important. Don’t stand them in full sun, this will dry out the flowers and they’ll start to wilt. A cool spot, out of direct sunlight is ideal – avoid sunny window sills, hot porches or conservatories

  • Every couple of days check the water in the vase, and if you can, change it for fresh water, re-cutting the stems at the same time. This is particularly important if you have an opaque vase as you can’t see what’s going on. There’s nothing worse than tipping a vase full of smelly water down the sink!
  • Some summer flowers are known water polluters, so their water should be changed everyday. Stocks, nigella, statice and larkspur are some of the worst offenders. If you add flower food when you change the water this will help to keep them longer lasting and smelling fresh.

You can get our blog posts delivered for free by email - simply add your email address to the box below or alternatively grab the RSS feed.

Don't forget to follow Interflora on Twitter

Charlotte Barnes

Post category: Best Posts, Care Tips, How-to Guides, Knowledge  

{ 0 comments… add one now }

Please Leave a Comment

You can use these HTML tags and attributes: <a href=""> <b> <blockquote> <code> <em> <i> <strike> <strong>