For many new gardeners, both indoors and out, keeping plants alive can be a challenge. While there are lots of reasons a plant may die, there are some basic things to do that can keep plants not just alive, but thriving. Don’t throw in the trowel and blame your ‘brown’ thumbs if a plant dies. Try to work out what went wrong, and learn how to succeed better next time.

First up – always read the manual. It’s not a long read as ‘the manual’ for a plant is its label. The information on the label outlines growing conditions – such as sun or shade – the best soil conditions, the plant type, its expected size and its flowering season. Click here to learn more about the importance of reading your plant labels.

One of the top reasons plants die is that they never actually get planted! Plants left forever in the pot that they come home in from the garden centre, especially if they get forgotten and are not watered, will die. If you can’t plant a new purchase immediately, put it in an obvious place so you remember to water it until you can get it into the ground.

Is your plant on the way out, like this sad Spathiphyllum? Scroll to find out why...

 

20 reasons why plants die

Once plants are in the ground or transplanted into a larger pot to grow indoors or out, there are still things that can go wrong. Some may be obvious when the sick or dead plant is inspected, but others may leave you scratching your head. Here are conditions or situations that can affect the health and wellbeing of plants and, if left unchecked, could lead to plant death.

 

Reason #1: Not enough water

If soil or potting mix repeatedly dries out, and especially if the plant wilts or shows signs of brown or dying leaves or shoots, then your plant isn’t getting enough water. If this keeps happening, the plant will become stressed and may die. Dry soil or potting mix may also be hard to rewet, compounding the problem. Water all plants regularly, especially those in containers and plants sheltered from rain (such as those growing under the eaves). If plants are dry, don’t wait and hope for rain – water them! On hot days it may even be necessary to water plants several times a day. If a plant has dried out and is hard to rewet, apply a soil wetting agent such as Saturaid. Plants in containers that have dried out can be dunked in a bucket of water to rehydrate the potting mix. Where plants are watered by irrigation system, regularly check that all irrigation jets are functioning properly. Occasionally they can become blocked, leaving one or more plants without water despite the system running regularly.

 

Reason #2: Over watering

Too much water can be as harmful as too little water, particularly for plants in containers (indoors or out). Make sure the soil or potting mix is beginning to dry out before watering again (use your fingers to gauge how wet or dry the soil is just below the surface). Empty plant saucers and check that drainage holes are allowing water to drain from the pot – most plants don’t like to sit in wet or waterlogged soil. Want more info on the right watering balance? Here's a note from your plants on watering.

 

Reason #3: Too little care (general neglect!)

While a few plants do thrive on neglect, most plants need regular care and attention. Get into the habit of looking carefully at plants – whether indoors or out – and looking at your garden regularly. Being familiar with how a plant should look means you’ll recognised the signs if something is going wrong allowing you to check for problems and provide a solution. Here are some more tips for neglectful gardeners.

 

Reason #4: Over-fertilising

Often, when a plant isn’t performing well, gardeners reach for the fertiliser. Extra food may not be what a plant needs and too much fertiliser can be damaging. As a general rule plants use fertiliser when they are actively growing and most established garden plants only need fertiliser once or twice a year. The exception is plants that are using lots of energy to provide fruit, flowers or edible leaves – these plants benefit from regular feeding. Indoor plants that are not growing probably don’t need much fertiliser and ferns need half strength fertiliser. Both the plant label and the fertiliser container has information about fertiliser needs and application rates. Here's some more info on the perils of over-fertilising your plants.

 

Always follow the directions on the fertiliser packet - too much food for a plant is not a good thing!

 

Reason #5: Unsuitable aspect in the garden

Choosing the most appropriate location for a plant helps it to grow strongly and reduces the chance it may die. Let the plant label guide you to selecting the best place for planting where the plant will receive the correct amount of sun or shade. Also be aware that some plants can be damaged by frost while others can suffer if conditions are too hot. Cold, hot or salt-laden winds can also damage plants. New plants that are buffeted by wind may also die as they fail to establish a strong, anchoring root system.

 

Reason #6: Unsuitable soil

Most plants grow best in a well-drained loam. In a container, select a good quality potting mix - Supersoil Professional Potting Mix is Flower Power's best general recommendation, but if your plant has specialist needs, consider a mix that's tailored to them - Flower Power's Supersoil Professional range carries specialist mixes to suit just about every plant type. Soil that’s sandy, poorly drained or too shallow will be challenging for most plants especially those that are newly planted. If soil is hard to dig, hard to keep moist or very wet, improve it before planting.

 

Reason #7: Planted too deeply (or not deeply enough)

Always plant at the same depth that the plant was growing in its nursery pot. Digging a planting hole that’s too deep or too shallow means the plant won’t establish in its new location and will slowly die. Sometimes plants that are too deeply planted don’t die but also don’t grow. When planting, water the plant in well, firm the soil with your hands (not feet!) and take care to avoid air pockets around the roots.

 

Reason #8: Root competition

If there are established plants in a garden, and a new plant goes into the same area, it may struggle to get enough water and nutrients to survive, as it can’t compete with the roots of other plants. Root competition may occur when planting near large trees or well-established shrubs. Having too many plants in a container can also lead to root competition.

 

Got indoor plants? It's a must to make sure you get the lighting spot-on.

 

Reason #9: Too little light indoors

Most plants that are grown indoors need bright light. If there’s too little light, plants gradually decline and may become stressed. Stressed plants are likely to be attacked by pests and diseases. To overcome a lack of light, rotate plants and spell them outdoors or in a more brightly lit spot. Also avoid positions where plants may be hit by bright, hot sunlight, which may damage foliage. Click here for tips on growing indoor plants in low light.

 

Reason #10: Draughts

Indoor plants can be killed if they are exposed to hot or cold draughts from heaters or air-conditioners. Ferns are particularly vulnerable to draughts. Check indoor plants at the change of seasons when indoor conditions change. The hot air expelled from air-conditioner motors positioned outside can also damage nearby garden plants.

 

Reason #11: Reflected heat

Plants that are growing near hot surfaces may be burnt or even killed especially during a heatwave. Move plants away from hot surfaces such as concrete paths or metal fences or lay down cardboard or shadecloth to give temporary protection.

 

Reason #12: Unchecked pest and disease issues

There are many pests and diseases that attack plants and some can lead to plant death. Root rot for example, which can be caused by a soil-borne pathogen such as a fungus or may occur in poorly drained soil, can cause a plant to die very quickly. Pests that are hard to see, such as scale, can also cause considerable damage before the pest is observed and treated. Possums that repeatedly eat new growth can also cause a plant to die. Click here to read Flower Power's comprehensive guide to identifying pests and diseases.

 

Pest infestations - such as mealy bugs on this fiddle leaf fig - can cause plant death if not controlled.

 

Reason #13: Pesticide damage

When using any pesticide to treat a pest or disease, always follow the directions carefully and read any warnings or cautions. Incorrect application even of an organic pesticide can damage plants and may lead to plant death.

 

Reason #14: Herbicide damage

Plants are often accidently damaged or killed when herbicides are applied near by to kill weeds. Avoid spraying on windy or hot days and always read the label. Hand-weed around garden plants and in garden beds.

 

Reason #15: Other chemical damage

Mysterious plant deaths may be related to the accidental tipping out of soapy water, a cleaning product or other waste material such as paint or bleach. Also, take care with chemicals used to clean windows or pathways, as they may damage your plants. Keep an eye on tradesmen who may not be as careful as you are with waste materials.

 

Reason #16: Whipper-snipper or mower damage

Ringbarking a tree or shrub by ‘whipper-snippering’ or mowing too close to the trunk can lead to plant death.

 

Heavy rain, hail and harsh winds can cause severe damage leading to plant death.

 

Reason #17: Storm damage

Heavy rain (especially flooding) can cause damage to plants. Hail can also damage plants by bruising or splitting bark or shredding leaves. Strong winds may dislodge plants and disturb roots. Sometimes storm damage is slow to kill a plant, especially a large plant or tree, and the weather event may be forgotten by the time the plant dies. Here are some tips on reviving your garden after heavy rain.

 

Reason #18: Other external damage

Wire, plant supports or ties that dig into the trunk or stem can damage the bark and lead to die back or plant death. Always remove the plant label at planting (but do read the information and keep the label indoors as a reference). Regularly check and loosen plant ties. Also avoid mounding up soil or mulch around a trunk, as this too can cause damage and potentially lead to the death of the plant. Soil compaction, for example, caused by parking on lawn under a tree can also cause plant death.

 

Reason #19: Dog pee

Yes, your pet’s wee can kill a plant! If your dog repeatedly wees on a plant or on the same patch of grass, that plant or grass may show signs of dying back. Hose off the wee, or protect the plant with a temporary barrier.

 

Reason #20: Life span

Plants don’t live forever, and some plants – known as annuals - only live for a season or two before they die off. Herbaceous perennials die down each year (usually in autumn or winter) but will regrow. Deciduous plants lose leaves over winter but regrow new foliage in spring.