Spring Fertilizer: It’s hard to believe March begins this week! With the approaching of March 1^st and the nice weather, some may be thinking about fertilizer applications. Three quick reminders:

1-Soil temperatures can be viewed at: https://cropwatch.unl.edu/soiltemperature. Soil temperatures below 50F allow for a slower conversion of ammonium to nitrate by soil microorganisms.
2-There was a high amount of mineralization that occurred last growing season due to the warm soil temperatures. Higher soil residual nitrate was common in soil samples in the area; thus, you can believe the fact that there’s a higher amount of soil residual nitrate and adjust fertilizer recommendations accordingly. If you’re unsure or if the soil samples didn’t pull well due to the dry fall conditions, soil samples can be pulled again this spring to gain confidence in recommendations.
3-Reminder of my nitrogen challenge! The higher residual nitrate provides a great opportunity in putting down a lower base rate and use a tool like sensor based fertigation via Sentinel Fertigation to apply only what the plant says it needs throughout the growing season. You could also consider an on-farm research study using a few different rates. Please let me know if you’re interested in these options.

Pruning Tips: With the coming of March also comes questions regarding pruning. My horticultural colleague, Elizabeth Killinger, shares some tips with some updated research on pruning timing for different plants. Full article: https://huskerhort.com/2024/02/25/a-pruning-primer/#more-1466.

“The first step to pruning is surveying the plant. This will ensure whether or not pruning is needed. Look for and remove any dead, diseased, damaged, rubbing, or crossing branches first. Remove suckers, little saplings at the base of the tree, and water sprouts, small vertical stems on the main branches. Also look at the plant in terms of safety. Be sure the plant is not blocking vehicle sight lines or covering sidewalks. Remove any low hanging branches that are hanging over a sidewalk.

Pruning Tools: In order to make cuts that heal correctly on plants, the proper tools are needed. When pruning small branches, those that are 1” in diameter or smaller, hand pruners are recommended. If you have to twist the pruners or take multiple ‘bites’ at the branch, a different tool is needed. For branches that have a diameter greater than 1”, loppers are recommended. Pruning saws are extremely sharp and work well to get into the tight places that the pruners and loppers don’t fit. They can also cut branches that are larger than 1.5” in diameter. The last tool of the trade is the hedge shears. They are used for shearing hedges or shaping plants and shouldn’t be used as substitutes for other pruning equipment.

Deciduous shade trees, It was previously recommended the best time to prune most shade trees was during winter dormancy. New research shows the optimum time to prune living branches is late spring and early summer because pruning at this time promotes the quickest sealing of pruning wounds, known as CODIT or Compartmentalization of Decay in Trees. Late spring and early summer is when tree cells are most active during the growing season, hence sealing occurs the quickest. 

Evergreen Trees keep their leaves throughout the winter. Pine trees rarely need to be pruned, if you choose to do so it is best done June into July, or when the new growth is between half and fully grown. If pine trees are pruned too early, the tree could be deformed and pruning too late could cause the tree to be stunted. Be sure to prune only the current years’ growth. If the trees are pruned too far back onto older growth, new growth will be delayed a year. Spruce and fir are two evergreen trees that rarely need pruning. If pruning is needed, they can be pruned between November and April.

Evergreen Shrubs, like arborvitae, Japanese yew, and juniper, are best pruned in late winter between November and April. The cuts will heal quickly and will be covered by new growth.

Deciduous Shrub pruning depends on blooming time. If the shrub blooms in the spring, before June 15^th, wait to prune until after it flowers. Lilac, forsythia, and dogwoods are considered spring bloomers. If the shrub is a summer bloomer, like a potentilla, flowering quince, or privet, then late winter to early spring is the best time to prune.”