The first step of germinating a plum seed—cold stratification—takes 60–90 days. Plum seeds must get sufficiently cold to germinate in the spring. After germination, create a good growing medium, plant your seeds, and keep them moist. The seeds should stay in a bright, sunny area and sit on a heating mat, too. Once your seedlings sprout, let them work on developing a strong root system before transplanting. Growing out their roots will take 1–2 years.
7 Steps to Germinate a Plum Seed
You are only 7 steps away from germinating a plum seed. Just keep in mind that the fruit created on the new tree will differ from the original plum. It could be better, or it could be worse. Following these steps to grow your very own tree is the only way to find out.
- Cold stratify plum seeds by putting them in the refrigerator
- Create a suitable growing medium for your seeds
- Plant your plum seeds in the soil and water them
- Put the pot in a sunny location
- Place a heating mat beneath the pot
- Make sure to always keep the soil moist
- Give the plant time to develop a strong root system
Plum seedlings develop a strong root system in about 1–2 years. After that, you can plant your fruit trees in the desired spots in your yard. Then, get ready for perfectly ripe fruit to set in the next 4 years.
Step 1: Put Your Plum Seeds in the Refrigerator
Plum seeds need to undergo the cold stratification process to germinate. In the wild, they would just sit on the ground through the cold winter months. Then, they’d be ready to sprout in the spring. You can mimic that process by putting your seeds in the refrigerator for 60–90 days. To keep them moist, place them in a plastic bag filled with damp peat moss or potting soil. Start this process early enough so that it ends right when the danger of frost passes.
Step 2: Prepare Your Growing Medium
Fully cold stratified plum seeds grow best in a seed-starting compost. The lightweight mix allows seedlings to pop through the soil without much effort. You can buy this organic compost already pre-mixed or make your own. To create a mix, combine four parts compost, four parts peat moss, and two parts vermiculite. Fill up one 8-inch (20 cm) nursery pot with soil for every plum seed you will grow.
Step 3: Plant Your Plum Seeds and Water
After the threat of frost ends for the year, it’s time to plant your plum seeds. Push each one about 1 inch (2.5 cm) down in the center of your soil-filled 8-inch (20 cm) nursery pots. Cover the top of the seed with soil. Then, add enough water to moisten the soil to 3 inches (7.5 cm) in depth.
Step 4: Choose a Good Spot for Your Pot
Place your pots in an area that will get a lot of sunlight each day. You can put them outside if there’s no danger of frost. Or place them inside right in a window that gets the most afternoon sun. Placing them under a full-spectrum indoor growing light can work, too, if you have that setup.
Step 5: Place the Pot on a Heating Mat
Plum seeds prefer the soil temperatures to remain around 68°F (20°C) day and night. To ensure that happens, place the pots on a heating mat. Set the attached thermostat to 68°F (20°C). The next day, use a soil thermometer to verify that the temperature is in the right range. Keep the seeds on the heating mat until the seedlings pop out of the soil. After that, you can take them off the mat.
Step 6: Keep the Soil Moist but Not Too Wet
Plum seeds need their soil to stay moist throughout the entire germination process. Their ultra-hard seed coats take a long time to absorb enough water to start the plant cell duplication process. Check the soil daily by pushing your finger about 1 inch down (2.5 cm). When the soil starts to feel dry, add enough water to moisten the top 3 inches (7.5 cm) of soil. Start watering deeper once the seedlings pop up. Deep watering will help your seedling grow roots.
Step 7: Let the Plant Develop a Strong Root System
Your seedlings will need to stay in their original starter pot for 1–2 years. They need time to develop a strong root system before transplanting. Moving your seedlings too early could leave them without the ability to absorb enough water and nutrients from the soil. Plan to plant your one- to two-year-old plum trees in the spring after the last frost. Choose an area with full sun and space the trees 12–20 feet apart.
Plum trees do not self-pollinate. So, always plant at least two compatible trees in the same area. You should get fruit that is ready to be picked within four years of transplanting your trees.
What is the Fastest Way to Germinate Plum Seeds?
There’s no good way to speed up the plum seed germination process. The seeds must go through the 60–90-day cold stratification process. Otherwise, they will not sprout once put in the soil.
- You cannot speed up plum seed germination.
- The 60–90-day cold stratification process is a must.
- Without cold stratification, the seeds will not sprout.
- Look for seeds beneath existing plum trees after winter ends.
- Plant those seeds directly in the soil to see if they germinate.
If you already have a plum tree, you could try to find seeds beneath your trees at the end of winter. You can then just plant the seeds because they already spent plenty of time in the cold. Finding the seeds is easier said than done, however. They often get covered up by leaf debris, pushed into the soil, or carried away by birds.
How Long Does It Take for a Plum Seed to Sprout?
Plum seeds take 7–30 days to sprout once put in the soil. However, a plum pit must first undergo cold stratification before it will sprout. The cold stratification process adds 60–90 days to the total. Overall, the germination process can take up to 4 months.
- Plums must undergo cold stratification before they will sprout.
- Colds stratification requires the plum pit to be exposed to cold temperatures for 30–90 days.
- Plum seeds sprout 7–30 days after being planted.
- With cold stratification included, the timeframe from seed to sprout is about 4 months total.
- Check your plum seeds daily to see if they’re growing.
- Keep the soil moist as you wait for your seeds to sprout.
- If nothing happens after 30 days, your tree probably won’t grow.
Check your plum seed daily for signs of life. Keep the soil consistently moist for the entire month after planting. The seed will not likely germinate if you don’t see any progress after 30 days.
Germination Timing for Plum Seeds
Expect the plum seed germination process to take 4 months total. The initial cold stratification process takes 60–90 days. The seed needs to stay moist in the soil for up to 30 more days to sprout. The soil should stay in the 68°F (20°C) range to ensure the seeds germinate.
- Plum seeds take up to 4 months to germinate.
- Cold stratification takes 60–90 days while the sprouting process adds 30 more days.
- The soil needs to stay moist and warm to help the seed sprout.
- Let your plum seedlings grow for up to 2 years in their original pots.
- Transplant your plum trees in a full sun spot and expect fruit within about 4 years.
Once the seedling emerges, water the soil a bit more deeply. Let your trees grow in their original pot for 1–2 years before transplanting. Plant the trees in a spot that gets full sun. Your efforts will reward you with fresh plums in about 6 years total.
Although germinating plum seeds can take a long time, it’s well worth the delicious fruit you will get. Just remember to let the plums fully ripen on the branch to enjoy their full sweetness in every bite.