Plant Materials Center Update

Here are 5 things that you should know about the PMC for April 20, 2023:


As of 4/13/23 sales stood at $1,708,016. That is 121% of the annual sales revenue budget of $1,114,300. Sales are over $200,000 ahead of where they were on March 30 of last year when they were $1,507,075. A total of 1,868,280 plants were harvested and so far, 1,820,489 have been sold leaving less than 48,000 remaining to be sold, or 2 ½%. 1,755,557 plants have been shipped.

The PMC started its annual COOLER BLOW-OUT SALE last week. It gives a 10% discount for purchases between $550 to %1,000, 15% for purchases between $1,001 and $1,500 and 20% over $1,500. It is going well. We have received several orders which help clear out some of the last of the plants still in the cooler.

End of Sales & Shipping Season

The PMC will turn off its cooler in early May. The plants have been in cold storage long enough and will deteriorate in the bags. Also, planting bare root seedlings close to the end of spring can result in the plants being subject to warm, dry weather before they begin to become established, causing additional stress. Bare root season is almost over. There is still time to get plants for another week or two and the current PMC availability can be seen on the PMC website at

Root Pruning Begins

Root pruning is the practice of cutting the tips of roots off the seedlings while they are in the ground using a specialized implement called an undercutter. The reason that is done is to cause the roots to branch, resulting in a more fibrous root system and a more vigorous seedling with better survivability. This first round of rot pruning focused on what will be the 2-year-old hardwood seedlings. Next month it will be the 2-year-old conifers turn.

Seed Stratification Wraps Up

Most species grown from seed at the PMC produce seeds that are dormant. Seed stratification is the practice of treating dormant seeds so that they readily germinate once planted. The treatment used most is cold, moist stratification. Seed lots are placed in a bag with damp perlite and placed in a cooler at around 34° F for 30 to 120 days depending upon species. These are the same conditions seeds experience in nature during winter. The last round of stratification was for those species requiring 30 days of stratification. The various stratifications periods are timed so that they are all ready to be planted in mid-May. At that time, they will be dried on drying screens so that they can be planted with the seed drill.

Fall Seedbed Begins to Germinate

The alternative to planting stratified seeds in the spring is to plant non-stratified seeds in the fall. Seeds planted this way receive an extended cold, moist period through winter and are ready to grow when the ground warms and the day length increases in the spring. This year the ground has been slow to warm, slowing germination for the fall seedbed. Fortunately, most species are germinating, just a little slower than usual. Hopefully, that continues.

I hope this helps. Please let me know if you have any questions. You can find older posts about the Plant Materials Center at

Jim Brown
Director of Nursery Operations