Don’t Make These 7 Watering Mistakes in Your Garden

Watering your garden can feel daunting. How often should you irrigate? What type of irrigation should you use? How much moisture do your plants need? It’s easy to get confused about soil moisture. To make matters more confusing, too much and too little water sometimes cause the same plant symptoms! 

Mistake 1: Overhead Watering

Spraying your plants with a hose from the top seems easy and logical. Sprinklers seem even simpler. After all, an even spray over a lawn is practically effortless? But you may have noticed lots of warnings about overhead watering. This practice may seem ideal at first, however it can cause lots of unwanted problems with your plants. It also wastes a lot of moisture. If you live in an area with summer droughts, conservation is super important to avoid a hefty utility bill.

Before we dig into why overhead watering can be bad for plants, let’s address a common myth: Overhead watering does not cause leaf burning! Many people think droplets on leaf surfaces can cause them to get scorched, but this is not the case. Prairies and forests all over the world do just fine with rain on their foliage.

The real issue with overhead watering is plant disease. When moisture sits on certain plants’ leaves, it creates conditions for fungi to thrive. We all know fungi love moisture! If you combine high humidity and low airflow (tight spacing) between plants, it is a recipe for disaster. 

Mildew and botrytis (gray mold) are the most common foliar diseases in the garden. These pathogens grow and spread very easily amongst wet foliage. In extra moist and humid conditions, the spores can fly in the wind to nearby plants and rapidly cover your plants in a fluffy white layer that hinders photosynthesis, reduces yields, and slowly kills plants. 

Other negative side effects of overhead irrigation include:

What To Do Instead

If you want to use a hose properly, simply lower the nozzle to the base of the plant. The goal is to water the soil, not the leaves! When you deliver moisture directly to the root zone, the plant can soak it up quickly. The soil can be irrigated more deeply, promoting deeper root zones and more resilience against drought. 

Overhead irrigation is fine for your grass or alternative lawn. But you should take special care to avoid it with these crops because they are more prone to foliar diseases:

Moisture on leaf surfaces predisposes these plants to powdery mildew, botrytis, blight, and other infections. Drip irrigation and soaker hoses are much more desirable. If you don’t have an irrigation system, remember to spray the hose at the base of the plant (directly wetting the soil) so you don’t wet the leaves.

For the record, a hose is perfectly fine for many plants. If you want to spray a few pots or beds, go for it. Watering early in the morning is ideal so the leaf surfaces can evaporate and dry out throughout the day. Overhead hoses are also super useful for watering in baby transplants. 

However, relying on an overhead hose over the long term can cause waste and is not super efficient. Directing irrigation at the base of the plants delivers moisture straight to the soil without wetting the leaves. An even better option is drip irrigation, or soaker hoses run underneath a layer of mulch.

Mistake 2: Choosing the Wrong Time of Day

The morning is ideal, but some rules are meant to be broken! Technically speaking, the best time to actually water your plants is when they need it. If a plant shows signs that it’s thirsty, there is no hard and fast rule for the best time of day to water. 

Every crop can be different, and it is more important to prevent drought stress than to water at a specific time of day. If it’s the middle of the day and your plants are thirsty, give it to them!

What To Do Instead

If possible, water in the morning. This is especially important in regions with very hot summers. Watering before the sun comes up is best in these situations. More importantly, learn to assess your plant’s needs (explained more below). Don’t stress too much about sticking to an exact time of day every day. Instead, take note of these key environmental and biological differences in irrigation timing.

Best: Irrigate in the Morning

Giving plants water in the morning is ideal but not essential. If you have flexibility in your schedule or you want to perfectly time your garden tasks, this is the best time.

The main reason why morning moisture is beneficial has to do with the natural cycles of the day. Light begins reaching plant leaves in the morning. The plant will use resources throughout the day to transpire, drink, and photosynthesize. It can use the moisture most efficiently when it receives it in the morning.

Least Ideal: Afternoon Watering

As you move toward the middle of the day, irrigation becomes less effective. If your plants really need a drink in the afternoon, go ahead and give it to them. But remember that blazing hot weather evaporates a lot of water before the plant can even use it. 

This is especially problematic on windy days. You could think that you properly irrigated your garden, only to discover the next day that the soil is totally dry because most of the moisture evaporated in the heat or wind.

Less Ideal, But OK: Evening Watering

If you water your plants from the base around sunset, this can be great for conserving moisture while it is cooler outside. However, overhead watering in the evening is the least ideal. If you must irrigate at the end of the day, always do it from the base of the plant. This ensures that the leaves stay dry before nighttime arrives.

There is only one real “rule” that professional gardeners and farmers follow regarding the time of day for irrigation: Avoid overhead moistening the leaves at the end of the day! Overhead moisture in the evening is a recipe for disease disaster. Fungal issues and rots easily creep into wet foliage that stays moist through cooler nighttime temperatures.

Mistake 3: Underwatering

It can be difficult to strike a balance between too little or too much hydration. The symptoms of underwatering and overwatering often look similar, such as drooping, yellowing, or poor production. The best way to know if you are underwatering is to check the leaves. 

Gauging Leaf Size and Moisture

It can be difficult to detect underwatering in plants with smaller leaves, like thyme or oregano. In these instances, it helps to look at the overall bushy structure to see if it is drooped or flattened. Happy leaves will be upright and fluffy or herbaceous. Dehydrated leaves will look flatter and sad.

But there is one key caveat to be aware of. Some plants naturally wilt in peak afternoon heat regardless of how much moisture they have. The Cucurbit family (zucchini, melons, cucumbers, and squash) is particularly known for wilting midday. The large leaves may droop to protect themselves from intense heat. However, a properly hydrated plant will perk back up in the cooler temperatures of the evening. If they don’t stand back up, it’s a sign to irrigate.

Different Plants With Different Needs

When it comes to deciphering the needs of different types of plant, observation is vital. Think about the water needs of a great Dane versus a chihuahua. The physical size of a plant is correlated with its energy expenditure. Generally, bigger vegetables need more. Trees and perennials operate a little differently if they have ultra-deep roots and grow natively in your area. The only caveat here is whether or not the plant is native, and whether it can withstand periods of drought.

Crops with extra large leaves and fruits (like squash) need a lot more water than a small pepper plant with medium-sized leaves and a small amount of fruit. Similarly, a giant tomato plant with tons of foliage and fruits requires significantly more hydration than a small lettuce plant. Drought-tolerant native plants are adapted to the summers in your region, so they may not need supplemental irrigation.

Impact of Container Size

Underwatering most commonly happens in larger containers or raised beds. Many gardeners don’t realize how much moisture it takes to hydrate a large volume of soil. Underestimating the requirements of a container leads to drought-stricken plants with shallow roots. 

Soil has many layers. If you only saturate the upper layers of soil, the plant roots won’t grow as deep because they don’t have to scavenge for water if it’s available near the surface. However, the surface layers of soil also dry out more quickly, especially in raised garden beds. The gravitational pull of an elevated planter enhances the drainage, which is great for preventing root rot, but it can also mean that the large container dries out faster if it is shallowly watered.

In contrast, deep irrigation soaks the lower layers of the container. Moisture can trickle farther down into the bed, so your plants grow deeper roots. The deeper reservoirs stay wetter for longer periods of time, ultimately preventing dehydration on hot days.

What To Do Instead

Mistake 4: Overwatering in Containers

While underwatering is most common in large beds and containers, overwatering is the biggest mistake for small container gardeners. It is especially problematic in solid, non-permeable containers like thick wood (a whiskey barrel), metal, or plastic. 

Drenching container plants every day is a red flag. If you find yourself watering plants every single day, you may be accidentally giving them too much love. Some plants, like a tomato in a 3-gallon pot, will need moisture every day. Generally, a large plant in a small container needs more moisture. But most plants can suffer if they are repeatedly soaked on a regular basis. 

What To Do Instead

Instead of following an exact schedule (i.e., water every two days for five minutes), learn to use your observation skills. The frequency changes dramatically with the weather and plant growth stage. 

Always check soil moisture before adding more water! You don’t need a fancy probe or moisture monitor. Instead, the finger test is the most reliable way to check soil moisture.

Additionally, it is very important for container gardeners to select pots with large drainage holes. The water needs somewhere to exit at the bottom of the pot. This choice alone can help prevent overdoing it.

Mistake 5: Choosing the Wrong Tool

Watering cans are cute and functional for small spaces, but they are not the right tools for medium or large gardens. A small watering can does not typically deliver the right amount of moisture to raised garden beds or large containers. It is also awkward to carry back and forth to refill. However, watering cans work in a pinch.

Similarly, a standard lawn sprinkler system is not typically the tool-of-choice for vegetable gardeners. Sprinklers cause all the problems with overhead irrigation that we discussed above. Moreover, they can cause an overgrowth of weeds because they water all the pathways and spaces between plants, rather than focusing moisture on your crop root zones.

If you want to efficiently use your time and effort, it’s best to invest in a quality hose, nozzle, and storage system.

What To Do Instead

For most gardeners, a 50-80 foot retractable reel hose is an ideal setup. It allows you to efficiently bring your hose anywhere in the garden. An adjustable nozzle ensures you can change the spray. Mostly, you will need a shower hose setting to gently water transplants and deliver lots of hydration to the base of mature plants. Occasionally, you may use the blast settings to hose down an aphid infestation or clean off a muddy pathway.

Also, consider how you will store the hose for easy access and use. A retractable wall mount is an awesome option because it wraps the hose inside of a protective container. Some of the options for hose housing swivel around so you can easily angle your hose to different areas of the garden. As you pull the hose out to farther distances, it extends with ease. Better yet, you don’t have to roll up your hose when you’re done. The contraption naturally contracts the hose to roll it back in for a neat, tidy, easy-to-use system.

Lastly, be sure you have multiple hose accessories on-hand. A quick-release nozzle is ideal so you can easily interchange the hose heads. A long-handled wand is best for taller people who need to water at the base of plants, over greenhouse nursery tables, or anywhere you may need to reach. Instead of bending over and hurting your back, you can hold the base of the metal hose wand from a standing position. 

One extra cool bonus about retractable hose wall mounts is the ability to use aerial inoculants straight from your hose. If you’ve ever experimented with beneficial inoculants or preventatives (like compost tea or neem oil), or foliar feeding (applying liquid fertilizers to the plants rather than the soil), there are versions of this tool that make it even easier! In these versions, the spray applicator attaches straight to the quick-connect hose top and allows you to dilute your foliar spray as you deliver it.

Mistake 6: Treating Every Plant the Same

Beginner gardeners often forget that every plant in their garden has different needs. We discussed earlier how a great Dane obviously requires more water than a chihuahua simply due to their size difference. But many species also need different amounts of moisture simply based on where they come from. 

For example, a desert armadillo can probably go for longer periods without hydration compared to a semi-aquatic turtle. The same obvious differences exist between a cactus and a lotus flower. Every plant has a unique origin where it evolved. The amount of water it needs depends on its:

Do not assume that you should water all your plants the same! Instead, try to get to know them on an individual basis. If this seems overwhelming, start by looking for plant family patterns first.

What To Do Instead

Plants are like people: they all have different needs and preferences, and these change throughout their lifespan. Here are a few ways to become more in-tune with your plants’ unique needs based on plant type and life stage.

Plant Families

Vegetable gardens include a few common groups of plants with similar needs. Understanding plant families helps with pest control, fertilization, spacing, disease prevention, and of course—watering.

The most common plant families in most gardens include:

Vegetables vs. Herbs

It makes sense that a tomato generally needs a lot more water than an herb like rosemary or thyme. Tomato plants have tons of leafy growth and big clusters of tomato fruits. Considering that a tomato fruit is made up of up to 95% water, these plants logically need a lot of soil moisture to fuel the growth of huge fruit clusters.

In contrast, an herb like rosemary or thyme has thinner leaves with woodier branches. The herbs produce flowers, which requires significant energy, but the blossoms are not super fleshy or high-moisture content like a tomato fruit. 

A nice middle-ground example is a pepper plant. Peppers grow fairly stout to the ground and stay a lot smaller than their tomato cousins. They don’t have as many leaves and they tend to be more heat-tolerant because they come from the hottest regions of the world. A pepper plant also produces less overall fruits than a tomato. This means they don’t need as much water, but it’s best to not let them dry completely. 

Growth Stage

In general, crops need a lot more water in the fruiting stage compared to the vegetative (early leaf growth stage). A pregnant mother has to consume a lot more food and water to support her growing babies, so it’s fun to think of your fruiting plants as pregnant moms. They need extra resources to funnel toward the tomatoes, zucchini, pea pods, peppers, melons, or other fruits. 

It’s best to monitor your plants and increase watering once they start to produce flowers and fruit. A lack of water in this stage can dramatically hinder your yields. 

Seasonality

Summer or late summer watering needs tend to be double or triple what they were in the early transplant stage. Fruiting plants are typically much larger and use a lot more energy than they were as seedlings. 

Moreover, the weather is much hotter. UV rays cause evaporation from leaf surfaces and soil surfaces. The drying effect of sunlight should not be underestimated! A layer of mulch can significantly reduce evaporation, so your beds stay moist for longer.

Cooler spring and fall seasons naturally bring less watering frequency. The temperatures are lower and the weather is more moist in many regions. It’s important to monitor rainfall so you don’t overwater your plants. 

Mistake 7: Poor Garden Planning

Think about what you want to grow in different areas before you plant! “Chaos gardening” is a fun way to scatter leftover vegetable or wildflower seeds around. But garden planning is crucial for serious growers who want to maximize their space and harvest significant amounts of food. 

Some plants just don’t grow well next to each other. Others can outright harm or kill each other. But the main watering mistake has to do with grouping plants based on water needs.

If you grew a giant thirsty pumpkin patch next to a drought-tolerant flower bed, neither group of plants will do well. It becomes annoying to water one plant a little more while trying to water the other one less. Either the pumpkins would miss out on the moisture they need to grow giant squash, or the flowers would be unhappy due to overwatering.

What To Do Instead

Group plants together based on their water needs. This makes your irrigation tasks a million times easier! You can plant whole beds or areas with species that require similar amounts and frequencies of moisture. Then you can turn on irrigation lines or use a hose to deliver water without worrying about individual plant differences.

Notice how these combinations also include complementary growth structures. Peppers and zinnias both remain stout so they don’t shade each other out. A tomato plant grows tall, but lettuces appreciate the dappled shade to prevent them from bolting in the summer heat. 

The science and art of companion planting is an intriguing and nuanced topic. Most importantly, make your life easier by grouping similar crops together.