Spring is on the way, and in this transitional period, local experts and plant lovers have advice for people who would like to prep their garden or give their houseplants extra sunshine ahead of the growing season.
NSU freshman David Cox is a plant enthusiast with at least 80 plants of all different sizes hanging around his apartment.
“It’s all kind of a growing collection,” said Cox.
Although he never really planned to own this many plants, Cox said he has a love and affinity for them. His favorite are tropical plants with “striking, bold foliage.” Cox adopts a hybrid method for ensuring that his flora stay well lit.
“In the winter, I’ll keep [my plants] inside with grow lights,” he said. “During the summer, I like to put them outside.”
Despite typical frigid temperatures this winter, warmers days have been popping up every so often in recent weeks, something Cox has been taking advantage of. As he is “young and able-bodied,” Cox will take his plants outside during the day to soak in the sun and bring them in before temperatures drop too low.
However, Cox has some tips for people who might not be able to bring their plants in and out on daily basis, including using grow lights and working with the windows they have.
“Plants are a lot more adaptable the we give them credit for,” he said. “My best advice is to research plants that do better with the environment you have.”
Cox said he pays attention to the last and first frost date to know when to move his plants outside for the season.
“Usually around March, they will go outside and stay outside,” he said.
Jodie Parolini, Cherokee County Oklahoma State University Extension office agriculture educator, said the last frost-free date for the area is around April 11.
“Some places will say earlier and some will say a little later,” said Parolini. “With that being said, it is a rough estimate. We all know that Oklahoma weather can change pretty quickly, so there is always a slight possibility that we may get another freeze after this point. Instead of marking a date on your calendar of when you’re going to plant your garden, look at the temperatures of when you will plant your garden.”
If another freeze comes after April 11, Parolini said not to worry about plants that have already been placed outside.
“Your plants, depending on the crop, may still be able to make it,” she said. If we know that a frost is coming, you can try to make a little greenhouse around your plants to hopefully protect them.”
The U.S. Department Agriculture has a scale of different freezes. Thirty-two to 29 degrees Fahrenheit is a light freeze, where tender plants are killed, with little destructive effect on other vegetation; 28 to 25 degrees Fahrenheit is a moderate freeze with a widely destructive effect on most vegetation and heavy damage to fruit blossoms, tender and semi-hardy plants; 24 degrees Fahrenheit and less is a severe freeze, with heavy damage to most plants.
“At these temperatures, the ground freezes solid, with the depth of the frozen ground dependent on the duration and severity of the freeze, soil moisture, and soil type,” the USDA states.
Parolini advised gardeners also keep soil temperatures in mind.
“We will not be able to plant crops no matter how cold hardy if the soil is frozen over,” she said. “There are methods you can do to help warm up the soil quicker so we can plant sooner, such as raised beds, low tunnels, plastic mulch, and so on.”
In the transition from winter to spring, there are optimum growing temperatures for “warm season” and “cool season” crops.
“Cool season crops that are hardy include peas, radish, spinach, leek, garlic, kale, broccoli, brussels sprouts, and many more,” she said. “Cool season crops that are half-hardy include: beets, carrots, celery, lettuce, potatoes, chard, and many more.”
Brussels sprouts, for example, can tolerate a max temperature of 75 degrees and a minimum of 45 degrees. Their optimum growing temperature range is 60-65 degrees.
“Warm season crops that are tender include: cowpea, soybean, tomatoes, sweet corn, New Zealand spinach, and snap bean,” she said. “Warm season crops that are very tender include: cantaloupe, cucumber, eggplant, okra, pepper, squash, and many more.”
Parolini said it is better to grow a cool season crop that is hardy to half-hardy in the spring when it’s still a little cool out.
“I would not jump straight into planting your warm season crops at this point,” she said.
Planning ahead is critical to a successful garden.
“What do you want your garden to look like? Map out your plan by writing it down,” said Casey Hentges, OSU Extension associate specialist and host of Oklahoma Gardening. “Make a list of the plants you love and want to grow. It may help to walk your garden space and make note of where the sunny and shady areas are located. This information will help with plant selection.”
Hentges said not to let a previous failure deter this year’s plans. It’s important to keep in mind what worked – and didn’t – last year and learn from it.
“It can be easy to get in over your head and become overwhelmed. Start small this year with just a few plants or containers. You’ll be able to adjust as the season moves along,” said Hentges. “Our growing season can go well into the fall, so there’s plenty of time to adjust your plan.”
Parolini said the winter months are a great time to think back on the growing season.
“Were there any diseases present last year? If so, it may be time to do a crop rotation,” she said. “Try planting your tomatoes where you had your corn last year, or plant your corn where you had your soybeans.”
Before deciding to plant, Parolini said she “always, always, always” recommends gardeners get a soil test done.
“Do this many weeks – or maybe even a month – in advance so that way you can hit the ground running in the spring. It does take us some time to get the soil sample results back to you so you have to factor in that time as well,” she said. “Getting a soil test allows you to know what is going on in the soil nutrient-wise.”