A plant growing in the wrong sun situation will, at best, never thrive or grow to its fullest potential. At worst, you’ve condemned that plant to death, sometimes a surprisingly quick one.
This is why matching the type of plants you’re growing to the sun conditions in your outdoor spaces is one of the main keys to gardening success. (Along with consistent watering, providing good drainage, and regularly replenishing the nutrients in the soil.)
Let’s look at how to make sense of your sunlight situation and pick the best plants for your Texas garden based on the results.
HOW SUNLIGHT CHANGES IN TEXAS YARDS THROUGHOUT THE YEAR
I moved into my north-facing home in the middle of winter. The Texas sage and other shrubs in my landscape were barely getting any sun at all because my house was blocking all but the very early morning hours.
So when I bought my first annual flowers to plant out front in early spring, I grabbed blooms that preferred partial shade without even thinking about it. Instead of showy flowers, all I got were frizzled-up leaves. That’s because my front beds receive full, unrelenting sun in the warmer months.
The level of sunlight in your yard is constantly changing. There might be a spot that gets lots of sunlight one part of the year and barely any during the other three seasons. This is why understanding your sunlight situation can be complicated and even frustrating.
Let’s do a quick review of why this happens.
Since Texas (and the rest of the United States) is in the Northern Hemisphere, we’re tilted away from the sun during our winter months. This means we have shorter days (including the winter solstice, the day when we enjoy the least number of daylight hours). Shorter days, of course, mean fewer opportunities to get much-needed sun to our plants.
This doesn’t really make that much of a difference to many of the plants growing in your landscape; they just go dormant. The decrease in day lengths matters most to our edible plants that we want to keep producing for us during our winter months.
During the winter, the sun also stays at a lower angle in the southern sky. On the bright side, plants grown on South-facing covered patios or balconies that might only enjoy morning and evening sun in the summer can now feel direct sunlight on their leaves. On the negative side, even a small tree can now cast a large shadow. If your garden is on the northern side of a large object, it could spend all winter being shaded.
Just when winter light has you despairing, there’s a bonus! Deciduous trees drop their leaves, and spots that were once shaded will now receive sunlight.
In the summer, Texas is tilted toward the sun, and the sun is much higher in the sky. Throughout the day, sunlight is concentrated over a much larger area.
HOW TO CHECK YOUR LEVEL OF SUNLIGHT
Here’s the simplest way to measure your average sunlight exposure: Pick a clear day in late spring to early summer to observe your outdoor space from sun up to sun down. This timing assumes that any large trees in your yard have filled back in and could potentially block the most light.
Head outside every hour or so and jot down observations about each planting area. Is it bathed in sunlight or in shade? Is the sunlight dappled?
At the end of your observation day, add up your total estimate of how much sun each spot gets on average.
To consider an area a full sun location, it should receive at least 6 to 8 hours of direct sunlight. The bulk of these hours will likely fall between 10 am and 4 pm.
Your garden will, again, receive less sunlight from late fall to late winter. That’s okay because most of our cool-season veggies can thrive with fewer hours of direct sun (more on that later).
Now that you have a better understanding of your sunlight situation, you can match it to the preferences of the outdoor plants you want to grow.
DOES A VEGETABLE GARDEN NEED FULL SUN?
If you’ve concluded that your garden does not receive full sun, don’t despair. Six or more direct sunlight hours per day throughout the year is ideal, but it’s not a requirement to have a vegetable garden. There are still lots of yummy things you can grow, and we’ll get into your best options soon.
If you’re setting up your vegetable garden, it is, of course, a good idea to prioritize sunlight when selecting a location. Your goal should be to get as much sunlight on your garden as possible. If you live in the city, this can be more difficult thanks to tall buildings and too-close neighbors. Even in the suburbs, you’ll find barriers like trees and tall fences.
Whenever possible, try to place your garden on the south side of any large structures. Remember, during winter, these structures will block most of the sunlight from whatever is on the north side of them.
How many hours of full sun does a vegetable garden need?
The bare minimum number of hours per day is 4. I’ve got two pieces of good news for you.
Good news number one: There are a number of plants that can grow and produce for you with only 4 hours of sun. Good news number two: Even if you live in the most cramped of urban quarters and have the tiniest of covered balconies, you will most likely be able to provide your plants with 4 hours of sunlight at some point during the day.
DOES A VEGETABLE GARDEN NEED MORNING OR AFTERNOON SUN?
If you only have one sunny spot in your yard or outdoor space, then you can skip this part. For those of you who have multiple sunny areas where you could grow veggies, pick the spot that gets morning sun and afternoon shade.
Many plants need full sun in order to form flowers and set fruit. Even these sun-lovers can struggle under a blazing sun during periods of dry heat like we tend to have in summer here in many parts of Texas.
Pretty much every plant is happier when it can get most of its sunlight during the earlier part of the day and then enjoy some afternoon/evening shade when the temps are highest.
If you see plants labeled as “part shade” at the plant nursery, these plants especially will appreciate afternoon shade. They often cannot handle intense late afternoon sun.
You can give a plant some much-needed shade by growing it next to a taller plant or tree that will block direct sun in the afternoon. You could also plant it on the east side of a tall structure.
HOW MANY HOURS OF SUN DO VEGETABLES NEED?
All plants need sunlight for photosynthesis. Without sunlight, they wouldn’t be able to turn carbon dioxide and water into food. So if you deprive them of light, you’re essentially starving them.
That being said, not all edible plants need the same amount of sunlight. Plants that we grow for their leaves need less sunlight than plants that have to form large roots underground or ripen fruit. If you think of how much energy it must take to bear something as large as an eggplant or even a melon, it just makes sense that these plants would need more sunlight, right?
Here’s how to choose the right plant for your sunlight conditions.
Vegetables that only need 4 hours of sun
Veggies that can produce with only 4 hours of sunlight include leafy greens and herbs.
Small leafy greens like lettuce can actually survive with only 2 hours of light. Of course, when we say 2 hours here, we’re assuming the plants would still get several hours of indirect light throughout the day. (Anything under 3 hours of sunlight, by the way, is considered full shade.)
This is partly because a lot of our favorite leafy greens prefer the cool growing season. That means they’re already used to growing when our day lengths are shorter anyways. Too many hours of sun can actually cause them to bolt, or go to seed, because it signals to them that growing conditions are no longer ideal for their survival.
Herbs and leafy greens also don’t need lots of energy to produce large, heavy pieces of fruit and then support them while they take their sweet time ripening. They just have to grow leaves, and leaves don’t cost the plant quite as much.
Herbs like mint, rosemary, sage, and even basil will produce leaves for you with only 4 hours of light. If, however, you can offer them a little more light, they’ll grow much faster overall.
You should stick with herbs and leafy greens if you’re gardening indoors using only natural light from windows. You might think a plant placed in a south-facing windowsill is getting full sun, but in reality, that light coming through the window is not direct. Too much of it is diffused and reflected as it tries to pass through the glass. The light that makes it through is actually about 50 percent less intense than direct sun outdoors.
Herbs are the best plants for indoor gardening. They’ll be perfectly happy growing in south-facing windows. They also like east-facing windows that give them plenty of morning sun but afternoon shade. Herbs are forgiving of under-watering and will grow in pots only 6-inches deep. Plus, they’re really attractive plants. Houseplants that are low maintenance and give you leaves to season dinner? What more can you ask for?
If you’re hoping to grow plants with higher sunlight requirements indoors, you’ll need to supplement with a grow light.
Vegetables that need 6 hours of sun
Root crops like carrots, radishes, and beets will grow with 4 to 6 hours of direct sunlight per day. These guys need minimal maintenance once they’ve sprouted—just some supplemental water—and can be grown in containers at least 12 inches deep. If you’re gardening on a semi-sunny balcony, these are great options.
I said that fruiting plants need lots of sun. The two semi-exceptions are beans and peas. These guys can form lots of pods for you with only 6 hours of direct light. They might even produce with fewer hours, but they’ll take twice as long as normal to do so.
That means a garden space that barely gets full sun can produce all your favorite herbs, tons of leaves for your salad bowl and smoothies, carrots, and tons of crisp sugar snap peas.
Vegetables that need 8 or more hours of sun
Here’s where you’ll find the rest of the fruiting plants. Tomatoes, peppers, eggplant, squash, zucchini, cucumbers, melons, and okra all need at least 8 or so hours of sun for superior performance.
This group of sun-lovers also includes potatoes. The good news is, you can grow loads of homegrown potatoes in a pretty small area. If you’ve got one little sunny outdoor spot, stick a large grow bag there for spuds this summer.
Don’t try to grow any of these guys unless you have full sun in your garden. I mean, you could actually try. Plants can always surprise you. But you’re most likely going to be disappointed by the results.
Reminder, even these sun-loving plants benefit from some shade during periods of extreme heat such as we regularly experience in late summer. If you can’t give them some afternoon shade, cover them with a shade cloth to reduce the intensity of the light and to cool the area underneath the cloth a bit.
HOW TO TELL IF YOUR PLANTS ARE HAPPY WITH THEIR LIGHT SITUATION
A plant with lots of nice green leaves that’s producing whatever plant part you want to eat—leaves, juicy taproot, or little seed pods—within a normal timeframe is clearly happy with the number of sunlight hours it’s getting.
A good indication that plants aren’t getting enough light is when they grow leggy or lean over. “Leggy” describes plants that grow too tall and narrow, and they do this because they’re trying to get closer to their light source.
On the opposite side of the spectrum, plants will show signs of scorching or burning on their leaves if they’re getting more sun than they can handle.
You can always dig plants up and move them to a different location if they seem really unhappy where they are. Transplanting is a risk, but so is continuing to grow a plant in a spot that’s not ideal. Try to wait for a cloudy day to make the big move, and water the plant really well afterward.
You’ll probably find that plants moved to a spot with partial sun require less water than those in full sun. Make sure you don’t overwater them.
WHAT ABOUT FLOWERS FOR SUN AND SHADE?
I love growing flowers in the corners of my raised beds as well as in my flowers beds. Flowers have numerous benefits for a vegetable garden, in addition to lookin’ pretty (obviously).
My favorite full-sun flowers for my raised beds are pansies and violas in the cooler months and petunias in the warmer months.
If you’re looking for flowers to grow outside of your raised bed, here are some great options:
Flowers for sun
Texas lantana can turn into a small shrub with full sun. This hardy plant is the best choice for in-ground flower beds that get unrelenting summer sun and infrequent watering.
Other drought-tolerant plants include black-eyed Susans, yarrow, and blanket flowers. Zinnias are gorgeous options that will hang in there on even the hottest of days. With their startling orange, yellow, and pink blooms, they make a great addition to any space.
Nasturtiums are excellent full-sun options for Texas landscapes in spring and fall. Go for a variety with red flowers if you want to attract lots of pollinators and hummingbirds to your space.
Flowers for shade
Echinacea, AKA purple coneflower, needs only 4 hours of sunlight per day to form its beautiful purple flowers. (It can also handle full sun.) These are great flowers to plant near the back of your raised beds or in the ground.
I love to use sweet alyssum as a border plant or ground cover in large beds or containers. It only needs about 6 hours of sun and prefers partial shade during our hottest months.
Other great options are impatiens and skull cap and turks cap.