Birchas Ilanos/Blessing over the blossoming of fruit:
[One who walks around outside] in the month of Nissan, and sees trees which are sprouting forth blossom, needs to say the blessing of “Shelo Chiser Beolamo Klum Uvara Bo Brios Tovos Veilanos Tovos Leihanos Bahem Binei Adam.” This blessing is only said the first time that one sees the blossom that year.
Is this blessing only said in the month of Nissan or may it also be said in Adar or Iyar?
Some Poskim rule the blessing may be said also in the month of Adar or Iyar. Others however rule, based on Kabala, that one is to say this blessing specifically in the month of Nissan and cannot say it before or after. Practically some conclude that if one will be unable to say the blessing in Nissan he may say it before hand [in Adar], or after [in Iyar], upon seeing the blossom. However in the Rebbe’s opinion of the Alter Rebbe, the blessing may not be said in any other month.
If one saw the blossom and did not say the blessing, may he do so at a later date, when seeing another tree blossoming, or upon seeing that same tree?
Some Poskim rule one may only say the blessing the first time he sees a tree blossoming. If one saw the tree, and did not say the blessing, the opportunity is lost and he may no longer say it that year. However other Poskim rule the blessing may still be said upon seeing a blossom, even if he had previously seen a blossom and did not say the blessing at that opportunity. It however may not be said on a tree that has born fruit if one has seen a blossoming tree in the past. [Practically, one is to be stringent not to gaze at blossoming trees unless he plans to say the blessing. In the event that he gazed at the tree and did not say the blessing, many are accustomed to be lenient to still say the blessing, although it is suggested that one contact a Rav for a practical directive. If one did not gaze and stare at the tree but simply overlooked it as he was walking and the like, the blessing may be said the second time.]
- According to above if one did not say the blessing immediately upon seeing the blossom may the blessing still be said if he is still looking at the tree?
May the blessing be said even if he only sees the blossoming of one tree?
The blessing may be recited over the blossoming of even a single tree. However initially, it is best to say the blessing over the blossoming of two trees.
On what type of blossom may the blessing be recited over?
Seemingly the blessing may only be said upon seeing the blossoming of a future fruit and not the blossoming of a leaf or flower of the fruit tree.
If one sees fruit on the tree and does not see any blossom, may the blessing be said?
Once the fruits have grown, the blessing may no longer be said. However there are Poskim which rule that if one had not seen a blossoming tree beforehand, then it may be said. Even according to this opinion, it may only be said if the fruit has not yet ripened to the point that one may say Shehechiyanu upon eating it.
If most of the tree has its fruits grown and some are still blossoming may the blessing be said?
Are women to say the blessing of Birchas Ilanos?
May the blessing be said on Shabbos?
Yes. There are even those which are scrupulous to say the blessing specifically on Shabbos in order to complete the 100 required blessings. However others rule it is forbidden to say the blessing on Shabbos.
May the blessing be said over a mixed species tree, like nectarines?
One may not say the blessing upon seeing the blossoms of such a tree as the existence of such a tree is against the will of G-d. However there are Poskim that are lenient. Practically one is to be stringent.
May the blessing be said over an Arlah tree?
Some Poskim rule one may not say the blessing upon seeing the blossoms of an Arla tree. Other Poskim rule it is allowed. Practically one is to be stringent.
Safek Arla: According to all, in the Diaspora one may say the blessing upon seeing the blossoms of a tree in which one is uncertain if it is Arla. However in Eretz Yisrael it is not to be said.
 Seder Birchas Hanehnin 13/14; Luach 12/23; Michaber 226/1
 So is the Nussach of Michaber 226/1; Admur in Seder ibid; However some are accustomed to say “Davar”. See Piskeiy Teshuvos 226 footnote 13; Minchas Yitzchak 10/16
 Meaning, if one saw the blossom and did not say the blessing, he may no longer say it the next time he sees the blossom. [Ketzos Hashulchan 66/18] The blessing is said only on the first fruit tree that one sees blossoming, and not on any additional trees, even if they are a different species. [Mishneh Berurah 226/3; Unlike the law by Shehechiyanu, however similar to the law of seeing beautiful creations.]
 The question here is whether one is able to deduce from the wording in Shulchan Aruch of “Nissan” that the blessing may only be said in the month of Nissan. For a thorough discussion on this matter see Ketzos Hashulchan 66/18; Sdei Chemed Mareches Brachos 2.
 Machatzis Hashekel 226; Mishneh Berurah 226/1; Heishiv Moshe 8; Olas Shmuel [brought in Pesach Hadvir 2/226 that even according to Kabala this applies]; Sdei Chemed ibid in name of many Achronim; So is implied from the Peri Megadim 226 M”Z 1 that deals with the question of why we do not say the blessing every thirty days. [Ketzos Hashulchan ibid]; Minchas Yitzchak 10/16
The reason why Nissan was mentioned according to this opinion: The above Poskim explain that Nissan was mentioned in the Shulchan Aruch being it is the common time for blossoming. Hence in truth, the blessing may be said also in other months, by the first sighting of a blossom.
Calculating the year: If the blessing may be said in other months, how does the law that the blessing may only be said once a year come to fruit on? Does one calculate a year from when he blessed? Is it always calculated from Rosh Hashanah? If one said the blessing by the previous Nissan, may he now say it in Adar? If one saw it in Elul, may he now say it in Tishrei? A. Perhaps a year refers to the general blossoming season of each country, and not actually 365 days. Vetzaruch Iyun.
 The Sdei Chemed ibid rules that it may be said throughout the entire Tekufa of Nissan. The Chasam Sofer writes it may be said until Nissan of Tekufas Hachama. [Nitei Gavriel Pesach Vol. 1]
 Rebbe in Shaareiy Halacha Uminhag 1/220; Birkeiy Yosef 226/2 [in name of Mekuballim however in Moreh Baetzbah he implies that Bedieved it may be said afterwards]; Halachos Ketanos 2/28; Pesach Hadvir 2/226 [according to Kabala]; See Nitei Gavriel Pesach 1
Opinion of Admur: The Ketzos Hashulchan [66 footnote 18] writes that is implied from Admur in the Luach 12/23 that the blessing may be said in Iyar. This is implied from the ruling of Admur that after 30 days from saying the blessing the first time [in Nissan], the blessing should be recited without Shem Umalchus. Now, thirty days since the first recital in Nissan lands within the month of Iyar, and we see that Admur nevertheless learns that it is still applicable to the blessing. However the Rebbe in Shaareiy Halacha Uminhag 1/220 writes that from the Seder Birchas Hanehnin 13/14 one can derive the opposite law, that one may only say the blessing in Nissan. This can also be supported from fact Admur in the Seder does not explain that the word Nissan is not exact. It is also deduced from fact that he omitted the law of “if one may say the blessing again after thirty days“, which is written in the Luach. This omission is seemingly because in the Seder, Admur rules one may only say the blessing in Nissan, and hence saying it again thirty days later is irrelevant. [However alternatively one can explain the omission of this Halacha due to that in the Seder Admur rules that the blessing may only be said once, thus once it was said in Nissan the question of repeating it thirty days later is irrelevant.]
 Ketzos Hashulchan 66 footnote 18
 See Ketzos Hashulchan 66 footnote 18; Piskeiy Teshuvos 226/7
 Ketzos Hashulchan 66 footnote 18 in his understanding of Admur in Siddur 13/14; Chayeh Adam 63/1; Kitzur SHU”A 60/1; Machatzis Hashekel 226 in opinion of M”A 225/9, brought in Shaar Hatziyon 226/3
Explanation of Machatzis Hashekel: The Machatzis Hashekel 226 rules that according to the Rama the blessing may be said, as the Rama 225/3 rules regarding Shehechiyanu that it may be said the second time one eats the fruit, even if it was not said the first time. However according to those opinions [M”A 225/9] who argue on the Rama ibid by Shehechiyanu, that the blessing may not be said the second time, would rule here that the blessing has been forfeited.
Analysis on the opinion of Admur in Siddur-Opinion of Rebbe: From the wording of Admur it is implied that the blessing may only be said the first time that one sees the blossoming, thus if he saw it and did not say the blessing, it may no longer be said. This is implied from the fact Admur does not write that one may only say the blessing one time a year, as writes the Michaber 226/1, but rather writes that the blessing is only said the first time of sight, thus directly coming to exclude saying the blessing after seeing the blossom for the second time. This is also implied from the fact that Admur in the Seder omitted the Halacha regarding saying the blessing a second time after the passing of thirty days. [Ketzos Hashulchan ibid] However, it is evident that the Rebbe does not learn this way in Admur, as in Igros Kodesh 23/365 [printed in Shulchan Menachem 1/350; Shaareiy Halacha Uminhag 1/220] the Rebbe learns that Admur omitted this law due to that he holds the blessing may only be said in Nissan. Thus, according to the Rebbe’s understanding, there is room to learn in Admur that the blessing may be said the second time, so long as he sees it in Nissan.
 The reason-Why may one not say the blessing upon the second sighting and how it differs from Shehechiyanu? It requires further analysis as to why Admur implies to rule that by Birchas Ilanos the blessing may not be said by the second sighting. Regarding the blessing of Shehechiyanu said over fruit Admur does suspect for those opinions [Rama/Mahril] who hold the blessing may be said even if he already ate the fruit one time in the past, and Admur thus rules [Seder Birchas Hanehnin 11/13] that the blessing is said without Shem Umalchus, upon eating it a second time. Why does Admur not rule this way also regarding Birchas Ilanos? The Ketzos Hashulchan ibid explains as follows: Shehechiyanu is a blessing said as a result of one’s joy, and thus since it is possible to still receive joy even the second time one eats the new fruit, therefore Admur is stringent to suspect for the opinion of the Rama that requires Shehechiyanu to be said. However, Birchas Ilanos is a blessing said as praise to G-d for his creations, and not for one’s personnel pleasure. A proof for this can be brought from the fact that one only says the blessing one time a year, and if Birchas Ilanos were said due to one’s joy, then on would need to say the blessing on every species of blossoming trees that he sees, just as is the law by saying Shehechiyanu over each species of new fruit. From the fact that we do not rule this way we see that even according to the Rama the blessing of Birchas Ilanos may only be said the first time, and thus Admur does not suspect for this opinion. [Ketzos Hashulchan ibid]
 Maharil 143; Mateh Moshe 361; Mamar Mordechai 226/1; Elya Raba 226; Mishneh Berurah 226/5 and in Shaar Hatziyon 226/3 that so is implied from Michaber; Kaf Hachaim 226/10; Birchas Habayis 29/14; Hisorerus Teshuvah 1/104
 The reason: The Elya Raba and Mishneh Berurah ibid rule that Birchas Ilanos may be said upon seeing the blossom tree for a second time, if he did not say the blessing the first time he saw it. Their reason is because the blessing of Birchas Ilanos is said due to one’s joy, just like the blessing of Shehechiyanu. This is unlike the ruling of Admur as explained above. [See Ketzos Hashulchan 66 footnote 18; Piskeiy Teshuvos 226 footnote 5]
 Elya Rabah 226; Mishneh Berurah 226/4; See Q&A below regarding saying the blessing on a tre with fruit
 The ruling of the Ketzos Hashulchan in Admur is very persuasive and hence is difficult to ignore. Nonetheless, as stated above, the Rebbe did not learn like this inference in Admur. To avoid doubt one can simply hear the blessing from another person, or say the blessing together with a child, having the child say after him word for word [see Admur 215/2], thus educating him in the blessing, and at the same time being Yotzei according to the second opinion here.
 Ketzos Hashulchan 63 footnote 9; Seemingly this case has the same ruling as saying Shehechiyanu on a new fruit of which the Ketzos Hashulchan ibid rules the that as long as one did not go to another area, and is thus still staring at the new fruit, the blessing of Shehechiyanu may be said.
 Ketzos Hashulchan 66 footnote 18; See Kaf Hachaim 226/2
 The Chidah in Morah Bietzbah 198 writes that the blessing is said upon seeing two trees. [Perhaps this is hinted to in the plural statement of the word “trees” in this Halacha, as opposed to “when one sees a tree”] Nevertheless this is only Lechatchilah, and thus if the blossoming is only on one tree the blessing is to be said. [Vetzaruch Iyun regarding one who is stringent not to say the blessing upon the second sighting, even if he did not say it by the first sighting, as explained above, if he may delay the blessing when seeing a single tree.]
 Beir Heitiv 226/1 in name of Halachos Ketanos 2/28; Mishneh Berurah 226/2; Likkutei Sichos 23/116 [brought in Shaareiy Halacha Uminhag 1 p. 219; Shulchan Menachem 1/351]
Other opinions: Some Poskim rule the blessing may be recited even over non-fruit bearing trees. [Mor Uketzia 225; See Likkutei Sichos ibid]
 The reason: This is evident from [a) the blessing that we say “for humans to receive pleasure from” which is not applicable by non-fruit bearing trees, and] from the fact that the Michaber rules that once the fruits have grown the blessing may not be said. [Rebbe in Shaareiy Halacha Uminhag ibid]
 So is implied from the above ruling that the blessing may only be said over fruit bearing trees
 Michaber 226/1
 Elyah Rabah 226; Mishneh Berurah 226/4
 Mishneh Berurah 226/4
 Har Tzevi 226; Nitei Gavriel Pesach 6/6
 Nitei Gavriel Pesach vol. 1
 Lev Chaim 2/44; Bitzel Hachochmah 6/37; Beir Moshe 3/43; 8/79; Yechaveh Daas 1/2
 Nefesh David 2/19
 Moed Lekol Chaiy 1/9; Kaf Hachaim 226/3 “the custom is like this opinion”
 The reason: As one may come to pick the fruit off the tree, as well as that the blessing elevates the Divine sparks and is hence similar to Borer. [Kaf Hachaim ibid]
 Rav Poalim 2/36; Kaf Hachaim 226/11
 Yagel Yaakov 12 in name of Chasam Sofer 6/25 that the blessing is on the species and not the specific fruit
 Minchas Yitzchak 3/25; Yabia Omer 5/20
 Reb Akivah Eiger 226; Divrei Malkiel 3/2; Kaf Hachaim 226/11
 Dovev Meisharim 3/5; Neta Shorek 9; Chelkas Yaakov 56; Beir Moshe 3/43; Mishnas Yosef 1/6o
 Minchas Yitzchak 3/25; Yabia Omer 5/20
 Rebbe Akivah Eger says that he is in doubt regarding this, and rules that in the Diaspora, the blessing may be said because safek Arlah is allowed in the Diaspora.