2026 Christmas Tree Scouting Report April 2, 2026

Weather Update 

From March 25 through April 2, Pennsylvania saw a mix of warm days in the 50s-80s with periodic rainfall, which helped maintain soil moisture and push soil temperatures upward. These conditions supported early root activity and initiated bud swell in some areas, though development remained uneven depending on site. Soil temperatures have reached over 60 degrees. 

Looking ahead through the weekend, a significant warm up is expected with temperatures climbing into the 70s and even low 80s before a cooler, wetter pattern returns. This rapid swing will accelerate bud development and likely push trees from bud swell into early elongation, especially on warmer sites.

These conditions will also trigger increased pest activity. Warmer temperatures will drive mite egg hatch, scale development, and emergence of early season insects like weevils and midge. The combination of warmth and moisture may also favor disease development, particularly needle cast.

Overall, this upcoming stretch of weather is expected to move things forward quickly. Growers should be prepared for rapid changes in crop stage and pest activity and stay on top of scouting and timing.

Planting Reminders

As growers prepare to plant new Christmas tree blocks, taking time to plan spacing and layout will pay off for years to come. General recommendations often fall in the 5 to 8 foot range within and between rows, but the right fit will depend on species, site, and equipment. Many growers may choose 6 feet by 6 feet or 6 feet by 8 feet spacing, while others may go wider to allow easier access for spraying, mowing, shearing, and harvest. Remember to leave space in the field for access roads for spraying and harvesting. Starting with enough room for equipment, air flow, and long-term tree growth will make management easier over the life of the planting.

A few details at planting can make a big difference later. Set trees at the proper depth with the root collar at or slightly above the soil line, and make sure roots are straight and spread naturally in the hole. Avoid bent roots and J rooting, which caused problems in some blocks last season and can affect stability and growth. Root dips may be used by some growers to help reduce transplant stress, but consistent moisture management after planting remains critical.

Weed control should be part of the planting plan from the start. Penn State recommends controlling perennial weeds before planting, then maintaining a weed-free band about 30 to 36 inches wide in the row while using mowing or a managed cover crop between rows. This system helps reduce competition, improve access, and support better long term growth.

Fertility should be based on soil test results and addressed prior to planting when possible. Penn State guidance emphasizes correcting pH and nutrient levels ahead of establishment rather than applying fertilizer directly in the planting hole, which can injure young roots. Nutrient programs should be built over time based on tree response and site conditions.

For herbicides, product selection should match tree age, weed pressure, and soil conditions, and all applications should follow the label. Penn State's weed management guide includes site preparation tools like glyphosate prior to planting, along with preemergence and postemergence options for use in plantations, with important considerations for timing and tree safety.

Starting with good spacing, proper planting technique, and a plan for weeds and fertility will set the foundation for long term success and make management easier throughout the rotation.

To calculate your own GDD, visit a site like this.

Pest Information

Balsam Twig Aphid

This newly hatched balsam twig aphid was found by removing 3 inches of a Fraser fir branch that had curly needles (typical aphid feeding damage), and pulling off each needle while searching for eggs and nymphs around where the needles were attached. The year-to-date growing days total for March 26, 2026 was 63.5, according to greencastonline.com for that zip code. The Integrated Pest Management for Christmas Tree Production Guide states that egg hatch occurs between 30–100 GDDs and that monitoring for egg hatch should begin by April 1. In this case, at least some eggs hatched before April 1. Consider treatment to prevent curled, twisted needles on current year’s growth if the trees examined are near harvest and naturally occurring predators are absent, and the populations of aphids are found to be unacceptable. Consider treatments that are least harmful to beneficial insects, because pollinators will soon be active, and always follow the instructions on the label.

Scale Insects

On calls for farm visits, we are seeing some instances of high populations of Cryptomeria scale and Elongated Hemlock Scale.  Some growers may be interested in Dr. Richard Cowles and DeWei Li's research findings using Talstar in the early season to control overwintering scale. He also provided a great explanation of active ingredients and modes of action. If you are a grower with higher populations and looking to try something different, here is the information provided by Richard S. Cowles, Ph.D., Agricultural Scientist, Connecticut Agricultural Experiment Station:

Tristar/Quasar is acting to kill the scales through systemic action. The key difference between dinotefuran and acetamiprid is that dinotefuran only moves upwards, whereas acetamiprid probably moves both upwards and downwards, which is unique among the neonicotinoids. This is demonstrated by the difference in the response of armored scales to a basal bark spray vs. a foliar spray. Safari is much more reliable when used as a basal bark spray than is Tristar/Quasar.  Acetamiprid has been successfully used as a bark spray when targeting scales for seed orchard trees is not suitable for plantations of smaller trees because the labeled dosage limit on a per tree basis is not sufficient to be effective.  This is probably because much of the active ingredient is translocating in the wrong direction – to the roots!  On the other hand, in a side-by-side comparison, acetamiprid is more active than dinotefuran when used as a foliar spray.  This is probably because it not only has somewhat greater toxicity to the scales than dinotefuran, but bidirectional translocation of acetamiprid may be beneficial for reaching the scale insects further within the canopy. Dinotefuran (Safari) is unique among products I have tested that is effective at labeled rates when applied as a basal trunk spray. It is more effective in this case because all of the absorbed active ingredient only moves upward in the trees.

The reason for emphasizing the importance of thorough wetting spray coverage in the canopy has to do with the absorption of the active ingredient through the bark. This is inferred from the fact that low volume sprays have not worked as effectively as wetting sprays, even when using the same amount of active ingredient per acre. 

Lastly, we are really not targeting an earlier stage of scale, even though the spray is applied earlier in the year!  The goal of a bud break spray timing is to kill overwintered mature scales before they start producing eggs. The result is that you will see no dead crawlers, rather you see a complete absence of crawler activity.  With post-bud break spray timing, you will see large numbers of dead crawlers that settle, start to feed, and then die. Target 0.15 lb. active ingredient per acre.

There are several reasons why acetamiprid has unique properties that are useful to Christmas tree growers. It is active against both aphids and armored scales.  Therefore, a bud break timing will control both balsam twig aphids and armored scales. Contrast this with imidacloprid (only kills aphids) and dinotefuran (only kills scales).  Furthermore, the environmental toxicity profile for acetamiprid is superior. It is about 2000x less toxic to honeybees than imidacloprid or dinotefuran. Furthermore, since it has a short soil half-life, it is much less likely to be expressed in pollen or nectar of plants blooming within your plantings and is less likely to be found contaminating nearby streams or ponds.

We appreciate Dr. Cowles sharing this information for our report this week. If any grower tries this method, please follow up with your results. 

White Pine and Pales Weevil

White pine weevil activity should be closely monitored in early spring as adults become active during the first warm periods, often when soil temperatures reach approximately 50 degrees. We do have readings over 50 degrees, and in some scouting areas, over 60 degrees. Adults move to terminal leaders where they feed and lay eggs, leading to the characteristic shepherd’s crook seen later in the season as larvae girdle and kill the leader. Scouting should focus on previous hotspots, as infestations tend to recur in the same blocks. Look for adult feeding, small resin droplets on terminals, and early signs of leader decline. Management is most effective when timed to adult activity prior to egg laying, with applications directed to the upper portion of the tree. Pyrethroid insecticides such as lambda-cyhalothrin, bifenthrin, or cyfluthrin provide effective knockdown of adults when applied at the proper timing. Infested leaders should be pruned and destroyed before mid summer to prevent completion of the life cycle.

Pales weevil should be considered a site driven pest, particularly in areas with recent harvest activity where fresh stumps are present. Adults are attracted to these sites for egg laying, and newly emerged adults feed on the bark of transplants and young trees, often causing significant mortality. Scouting should include evaluation of newly planted blocks near harvest areas, with attention to feeding injury at the base of stems. Cultural control remains the foundation of management, including removal of stumps, minimizing slash, and delaying planting where possible. Where pressure is high, protective insecticide applications to seedlings or stump directed sprays may be warranted. Products containing active ingredients such as permethrin, bifenthrin, carbaryl, or lambda-cyhalothrin are commonly used for protection against adult feeding.

General Observations

Douglas fir needle midge monitoring should be underway. Box traps placed beneath previously infested trees will capture adults as they emerge from the soil. Emergence typically begins around 50 to 100 GDD. Check traps frequently to identify the start of flight and peak activity.

Spruce spider mite eggs are present and should be monitored closely. Eggs are small, round, and reddish, found on interior needles. Hatch typically begins around 100 to 150 GDD but may be extended during cool springs. Focus scouting on inner canopy foliage and known hotspots.

Cryptomeria scale and elongate hemlock scale are present on Fraser fir. Early stages are difficult to detect, so use a hand lens to inspect the underside of needles, especially on interior branches. While crawler activity occurs later in the season, identifying infested areas now allows for better planning as activity increases with warming conditions. When distinguishing between these two scales, shape and color are key. Cryptomeria scale is typically round to oval and white to cream colored, often associated with mottled or patchy yellowing on needles. Elongate hemlock scale is more narrow and elongated, brown to tan in color, and often aligned lengthwise along the needle. Using a hand lens will greatly improve accuracy when identifying low populations.

Needle cast diseases are visible on Douglas fir. Rhabdocline needle cast appears as blotchy lesions with developing fruiting bodies, while Swiss needle cast presents as uniform yellowing with rows of black fruiting bodies on the underside of needles. Scouting should focus on last year's needles to confirm disease presence and severity, with fungicide timing aligned to bud break and early shoot development.

Across all pests and diseases, focus scouting on interior foliage, lower branches, and previously infested areas. Use a hand lens to improve detection accuracy and flag problem areas to support targeted management. Scout often as temperature changes are sure to kickstart activity!

Next Report

The next scouting report will be available on April 9, 2026. Reminder, please submit observations anytime prior to Tuesday, March 31, 2026, by noon to Kelly Piccioni at keg200@psu.edu to be included in the next report. As a reminder, you may also call into the hotline weekly for updates: 1-800-PENN-IPM (1-800-736-6476) option 5.