Whether you can grow hydrangeas under pine trees depends on the density of the trees canopy. If the canopy is too thick it will deprive the hydrangea of sun and rainfall. If the canopy allows some dappled light then you will be able to grow hydrangeas if you water them diligently and amend the soil.\n\n\n\nIf you have a pine tree that allows partial shade or dappled\nlight to reach the area where you want to grow hydrangeas then there are a few\nother conditions that you must get right first to ensure that your hydrangeas\nnot only live but thrive and produce beautiful blooms\u2026\n\n\n\nSoil and watering Under Pine Trees \n\n\n\nThe first and most important problem when planting a hydrangea is finding a clear area of soil as pine tree have an extensive and shallow root system. If the tree is an old established pine then you can remove some roots with an axe without causing any lasting harm to the tree. \n\n\n\nI personally have had to remove sections of root many times\nas a landscape gardener and the trees are never phased.\n\n\n\nOnce you have found space the next factor is\u2026\n\n\n\nSoil pH- The soil pH under pine trees will naturally be acidic as this is the soil that pine trees themselves prefer and the soil is likely composed of many generations of mulched down, decomposed pine needles which are also slightly acidic or pH neutral. \n\n\n\nIt should be noted that whilst pine needles are particularly acidic when the fall from the tree, once they have decomposed the resulting organic matter is either slightly acidic or pH neutral so pine needles will have less of an influence over soil pH then most people believe.\n\n\n\nFortunately hydrangeas do very well in acidic soil and notably there flowers will be blue if the are of the species Hydrangea macrophylla (Bigleaf hydrangeas). You can manipulate the colour of hydrangea flowers to turn pink by increasing the pH of the soil by adding lime or wood ash (which are both alkaline) although this is quite tricky to get right!\n\n\n\nSoil structure- The\nsoil structure underneath pine tree will not be ideal for growing hydrangeas\nhowever with a few amendments you can adjust the conditions so that they are\nbetter suited.\n\n\n\nWhat you will need to do is add lots of organic matter to the area of planting to a depth of over 6 inches and to a width that will accommodate the size of the root system of your hydrangea at full maturity.\n\n\n\nFarm manure, leaf mould, or just general garden compost are all good options as they will retain moisture incredibly well and allow for good drainage so water doesn\u2019t collect or pool around the roots. \n\n\n\nThey will also add fertility and maintain a soil pH of around 6-7. It is essential that you add this organic material as the main reason hydrangeas die is because they are not able to take up enough water from the soil. \n\n\n\nOrganic material such as compost will help maintain the correct moisture balance in the soil that hydrangeas love. \n\n\n\nMulching helps Retain Water Under Dry Pine Trees\n\n\n\nHydrangeas that are under pine trees with restricted access to moisture will benefit from regular mulching. \n\n\n\nApply a layer of mulch 2 inches thick on the surround soil of your hydrangea. \n\n\n\nKeep a distance of 6 inches between the mulch and the woody stems of the hydrangea as they do not like to be exposed to consistently moist material.\n\n\n\nMulch will improve the soil texture and retain water so that\nthe soils underneath remains at the right moisture balance for the roots of the\nplant. There are also the added benefits of:\n\n\n\nAdding nutrients to the soilStimulating the soils beneficial ecosystemSuppressing weed growth\n\n\n\nAdding mulch to the area around hydrangeas is most important\nstraight after planting as this is the time when the plant is most vulnerable\nto drought. \n\n\n\nYou can use many different materials for mulching but the best for dry conditions will be compost, manure and leaf mould as they have the best capacity for holding moisture yet they structure allows for good drainage which is perfect for hydrangeas. \n\n\n\nWatering Hydrangeas Under Pine Trees\n\n\n\nOne of the biggest challenges for plants under pine trees is\nmaking sure that they are receiving enough water. \n\n\n\nPine trees can restrict the availability of water from\nrainfall by:\n\n\n\nIntercepting the rain in the canopy so that it doesn\u2019t reach the soil belowPine tress can soak up all the moisture in the soil with there extensive and thirsty root system and limit the available moisture for your hydrangea.\n\n\n\nThis means that regular watering of hydrangeas is essential\nin the spring and summer months as hydrangeas are thirsty plants.\n\n\n\nThe saving grace of being under a pine tree is that there\nwill be a good amount of shade which will stop the soil drying out so quickly. \n\n\n\nThe best way to maintain the optimal soil moisture for\nhydrangeas is to use soaker hose irrigation system which can gradually release\nwater slowly during the hottest days of summer. \n\n\n\nIf that\u2019s not possible then I would recommend watering your hydrangea with around 2 gallons of water once every two or three days during the growing season. The soil needs to be moist so if the surrounding soil is dry to a fingers depth then you will need to increase the frequency of your watering. In the hottest days of summer I would recommend water every other day. \n\n\n\nThis may seem like a lot of water but you have to bare in\nmind the hydrangea will be competing with the roots of the pine for moisture so\nit\u2019s important to monitor the moisture of your soil and adjust for the changing\nweather.\n\n\n\nDuring the Winter months your hydrangea should not need any additional moisture as it enters its state of Winter dormancy.\n\n\n\nIs There Enough Light for Hydrangeas?\n\n\n\nHydrangeas will have a tough time growing in full shade and even if they are able to establish they will not live up to their potential and produce lots of flowers.\n\n\n\nIf your pine tree is casting complete shade over your hydrangea planting site then I would consider the possibility of tactically removing braches to let the light in. Established pines will have no difficulty tolerating some pollarding (branch cutting) at any time of year, but winter is the best time to do this.\n\n\n\nHydrangeas of all species thrive in morning sun with shade\nin the afternoon. They can grow in full sun but shade slows the rate of soil so\nsome shade is preferred. \n\n\n\nIf your pine tree cast consistent dappled light on the\nground below then this will be enough to grow hydrangeas as long as the ground\nhas been enriched with plenty of organic matter.\n\n\n\nBig Leaf Hydrangeas are the species that grow best in the shade...\n\n\n\nThe Best Hydrangeas\nfor Growing Under Pine Trees\n\n\n\nThe best species of hydrangea to grow in shadier conditions\nis Hydrangea macrophylla commonly called \u2018Bigleaf hydrangeas\u2019. \n\n\n\nThere are many cultivars of this species that produce beautiful flowers of many different colours to suit your personal taste and notably turn out luxuriant foliage (as the name suggests) and will looks attractive when the hydrangea is not in flower. \n\n\n\nBigleaf hydrangeas will produce flowers even in the shade and dappled light, but the more sunlight it receives the better the display will be.\n\n\n\nFertilizer is Necessary Under Pine Trees\n\n\n\nHydrangeas often don\u2019t need fertilizer if they are in good soil amended with lots of organic matter and receive generous mulch once or twice per year.\n\n\n\nHowever pine trees and hydrangeas both have relatively shallow root systems and therefore will both be in direct competition for nutrients so it is a good idea to add some feed to make sure they are not starved of the nutrients they need to produce flowers.\n\n\n\nHydrangeas are not fussy feeders so fortunately you can give them a general plant feed once in spring (March\/April) and then another feed in July to ensure a good display of flowers and healthy foliage. \n\n\n\nThere are however specific fertilizers for hydrangeas which\nI would recommend if you have poor sandy soils with low fertility.\n\n\n\nGranular slow release fertilizers are my favourite as they require only two applications per year and, as long as you follow the manufacturer\u2019s instructions there is a low risk of over fertilizing your hydrangea which can burn the roots.\n\n\n\nFertilizing should be done in conjunction with adding mulch\nas the mulch acts as a sponge to soak up water and maintain soil moisture, as\nwell as adding nutrients.\n\n\n\nTo add granular fertilizer it is best to rake back your\nmulch and apply the granules to the soil underneath then rake the mulch back\ninto place of the top of the fertilizer.\n\n\n\nDo not apply any fertilizer after the middle of August as\nthis will stimulate new softer growth at a time when the plant needs to direct\nits resources to preparing for its winter dormancy.\n\n\n\nConclusion\n\n\n\nGrowing Hydrangeas under pine trees is possible if there is\nsome sunlight able to reach the ground below. \n\n\n\nThe Bigleaf hydrangea species is most suited to growing in\ndappled light or partial shade conditions.\n\n\n\nThe canopy of pine trees can stop rain water from reaching\nthe soil below and the shallow root system can dry the ground beneath so it is\nimportant that you water you hydrangea regularly during the growing season with\naround a gallon of water every two or three days. \n\n\n\nAmending the soil with plenty of organic matter and adding\nregular mulch will be of great benefit retain moisture in the soil so that the\nhydrangea doesn\u2019t suffer drought.\n\n\n\nAdding fertilizer is often necessary as both pine trees and\nhydrangeas have shallow roots systems which compete for the same nutrients. A\ngranular feed twice a year will encourage luxuriant healthy leaves and a strong\ndisplay of fabulous flowers and scents.